TAC / TransAlta Corporation - SEC-arkiveringar, Årsredovisning, Fullmaktsutlåtande

Colorado Gas Portfolio Acquisition June 3, 2026 Mountain Peak Power, Colorado 2

EX-99.3 Exhibit 99.3 Colorado Gas Portfolio Acquisition June 3, 2026 Mountain Peak Power, Colorado 2 Advisories A base shelf prospectus of TransAlta Corporation (the "Company" or "TransAlta") dated December 9, 2025 containing important information relating to the securities described in this presentation has been filed with the securities regulatory authorities in each of the provinces of Canada.

TRANSALTA CORPORATION 18,230,000 Common Shares

SUPPL Table of Contents Filed pursuant to General Instruction II.L. of Form F-10 File No. 333-292019 Prospectus Supplement to the Short Form Base Shelf Prospectus dated December 9, 2025 New Issue June 4, 2026 TRANSALTA CORPORATION C$350,016,000 18,230,000 Common Shares TransAlta Corporation (the “Corporation” or “TransAlta”) is hereby qualifying the distribution (the “Offering”) of 18,230,000 comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-15214

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

Osler, Hoskin & Harcourt

EX-99.5 Exhibit 99.5 Osler, Hoskin & Harcourt LLP Suite 2700, Brookfield Place 225 - 6th Avenue S.W. Calgary, Alberta, Canada T2P 1N2 403.260.7000 MAIN 406.260.7024 FACSIMILE Calgary June 4, 2026 Toronto TO:    TransAlta Corporation TransAlta Place Suite 1400, 1100 1 St SE Calgary, Alberta T2G 1B1 Montréal Ottawa Vancouver Dear Sirs/Mesdames: New York TransAlta Corporation (the “Issuer”) We refer

UNDERWRITING AGREEMENT

EX-99.1 Exhibit 99.1 Conformed Version UNDERWRITING AGREEMENT June 4, 2026 TransAlta Corporation TransAlta Place Suite 1400, 1100 1 St SE Calgary, Alberta T2G 1B1 Attention: Mike Politeski Executive Vice President, Finance and Chief Financial Officer CIBC World Markets Inc. (“CIBC”) and RBC Dominion Securities Inc. (“RBC”) as joint bookrunners (the “Joint Bookrunners”), and Scotia Capital Inc., BM

June 4, 2026

EX-99.4 Exhibit 99.4 June 4, 2026 TransAlta Corporation TransAlta Place Suite 1400, 1100 1 St SE Calgary, Alberta T2G 1B1 Re: TransAlta Corporation (the “Corporation”) To Whom It May Concern: We hereby consent to the references to our firm name on the cover page and under the captions “Legal Matters”, “Interests of Experts” and “Documents Filed as Part of the Registration Statement” and to the ref

TRANSALTA CORPORATION BOUGHT DEAL TREASURY OFFERING OF COMMON SHARES TERM SHEET

EX-99.2 Exhibit 99.2 JUNE 3, 2026 TRANSALTA CORPORATION BOUGHT DEAL TREASURY OFFERING OF COMMON SHARES TERM SHEET A BASE SHELF PROSPECTUS DATED DECEMBER 9, 2025 CONTAINING IMPORTANT INFORMATION RELATING TO THE SECURITIES DESCRIBED IN THIS DOCUMENT HAS BEEN FILED WITH THE SECURITIES REGULATORY AUTHORITIES IN EACH OF THE PROVINCES OF CANADA. A PRELIMINARY SHELF PROSPECTUS SUPPLEMENT HAS BEEN FILED W

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-15214

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

Mountain Peak Power

EX-99.1 Exhibit 99.1 News Release TransAlta Announces the Acquisition of Two Fully-Contracted Gas Assets in Colorado and Concurrent $350 Million Bought Deal Offering of Common Shares The short form base shelf prospectus is accessible, and the final prospectus supplement will be accessible within two business days, through SEDAR+. CALGARY, Alberta (June 3, 2026) Highlights • Acquisition of two new

SUBJECT TO COMPLETION, DATED JUNE 3, 2026

SUPPL Table of Contents Filed pursuant to General Instruction II.L. of Form F-10 File No. 333-292019 Information contained herein is subject to completion or amendment. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. This preliminary prospectus supplement and the accompanying short form base shelf prospectus shall not constitute an

Filed Pursuant to Rule 433

FWP Filed Pursuant to Rule 433 Registration No. 333-292019 June 3, 2026 Colorado Gas Portfolio Acquisition June 3, 2026 Mountain Peak Power, Colorado 2 Advisories A base shelf prospectus of TransAlta Corporation (the "Company" or "TransAlta") dated December 9, 2025 containing important information relating to the securities described in this presentation has been filed with the securities regulato

Mountain Peak Power

FWP Filed Pursuant to Rule 433 Registration No. 333-292019 June 3, 2026 News Release TransAlta Announces the Acquisition of Two Fully-Contracted Gas Assets in Colorado and Concurrent $350 Million Bought Deal Offering of Common Shares The short form base shelf prospectus is accessible, and the final prospectus supplement will be accessible within two business days, through SEDAR+. CALGARY, Alberta

TRANSALTA CORPORATION BOUGHT DEAL TREASURY OFFERING OF COMMON SHARES TERM SHEET

FWP Filed Pursuant to Rule 433 Registration No. 333-292019 June 3, 2026 JUNE 3, 2026 TRANSALTA CORPORATION BOUGHT DEAL TREASURY OFFERING OF COMMON SHARES TERM SHEET A BASE SHELF PROSPECTUS DATED DECEMBER 9, 2025 CONTAINING IMPORTANT INFORMATION RELATING TO THE SECURITIES DESCRIBED IN THIS DOCUMENT HAS BEEN FILED WITH THE SECURITIES REGULATORY AUTHORITIES IN EACH OF THE PROVINCES OF CANADA. A PRELI

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive o

Reportable Segments(1)

Condensed Consolidated Statements of Earnings (in millions of Canadian dollars except where noted) 3 months ended March 31 Unaudited 2026 2025 Revenues (Note 4) 565 758 Fuel and purchased power (Note 5) 165 277 Carbon compliance costs 39 49 Gross margin 361 432 Operations, maintenance and administration (Note 5) 181 173 Depreciation and amortization (Note 13) 105 146 Asset impairment (reversals) c

Three Months Ended

News Release TransAlta Reports First Quarter Results and Reaffirms Annual Guidance CALGARY, Alberta (May 6, 2026) TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) today reported its financial results for the first quarter ended March 31, 2026.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive o

2026 Target(2)

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (MD&A) contains forward-looking statements.

TRANSALTA CORPORATION (the “Corporation”) Annual and Special Meeting of Shareholders (the “Meeting”) April 30, 2026 REPORT OF VOTING RESULTS NI 51-102 – Continuous Disclosure Obligations, Section 11.3 Matters Voted Upon

Exhibit 99.1 TRANSALTA CORPORATION (the “Corporation”) Annual and Special Meeting of Shareholders (the “Meeting”) April 30, 2026 REPORT OF VOTING RESULTS NI 51-102 – Continuous Disclosure Obligations, Section 11.3 Matters Voted Upon The total number of common shares represented by shareholders present at the Meeting and by proxy was 188,939,751 representing 63.55% of the Corporation’s outstanding

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 TRANSALTA CORPORATION (Translation of registrant’s name into English) 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive offices) Indicate by che

TransAlta Corporation Announces Results of the 2026 Annual and Special Meeting of Shareholders and Election of all Directors

EXHIBIT 99.1 TransAlta Corporation Announces Results of the 2026 Annual and Special Meeting of Shareholders and Election of all Directors CALGARY, Alberta, April 30, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TSX: TA) (NYSE: TAC) ("TransAlta" or the "Company") held its Annual and Special Meeting of Shareholders (“the Meeting”) on April 30, 2026. The total number of common shares represented by

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, April 29, 2026 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared the following quarterly dividend on its Cumulative Redeemable Rate Reset First Preferred Shares for the period starting from and including March 31, 2026, up to but excluding June 30, 2026: Preferred Shares TSX Stock Symbol Div

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta Appoints Mike Politeski as Chief Financial Officer and Grant Arnold as Chief Commercial Officer

EXHIBIT 99.1 TransAlta Appoints Mike Politeski as Chief Financial Officer and Grant Arnold as Chief Commercial Officer CALGARY, Alberta, April 20, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) is pleased to announce the appointment of Mike Politeski as Executive Vice President, Finance and Chief Financial Officer (EVP and CFO) and Grant Arnold as Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta to Host Annual and Special Meeting of Shareholders and First Quarter 2026 Results Conference Call

EXHIBIT 99.1 TransAlta to Host Annual and Special Meeting of Shareholders and First Quarter 2026 Results Conference Call CALGARY, Alberta, April 07, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation 2026 Annual and Special Meeting of TransAlta Corporation Shareholders On Thursday, April 30, 2026, TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) will hold its annual and special me

EX-99.3

99.3 99.3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive offices) Indicate

EX 99.1

EX 99.1 EX 99.1

EX 99.4

EX 99.4 EX 99.4

Items of Business

Contents Letter and Invitation to Shareholders 1 Notice of Annual and Special Meeting of Shareholders 5 General Information 8 About Our Shareholder Meeting 9 Mailing and Availability of Proxy Circular and 2025 Annual Report 10 How to Vote 12 Business of the Meeting 19 Item of Business 1: Election of Directors 19 Item of Business 2: Financial Statements 37 Item of Business 3: Reappointment of Audit

TransAlta Investor Day Highlights Solid Foundation and Attractive Growth to 2029 and Beyond

EXHIBIT 99.1 TransAlta Investor Day Highlights Solid Foundation and Attractive Growth to 2029 and Beyond CALGARY, Alberta, March 23, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) is pleased to host its 2026 Investor Day today, in Toronto and virtually. A subset of TransAlta's executive leadership team will discuss the Company’s outlook for the Alber

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta Corporation Announces Conversion Results for Series A and B Preferred Shares

EXHIBIT 99.1 TransAlta Corporation Announces Conversion Results for Series A and B Preferred Shares CALGARY, Alberta, March 17, 2026 (GLOBE NEWSWIRE) - Further to TransAlta Corporation's (TransAlta or the Company) (TSX: TA) (NYSE: TAC) press release dated March 2, 2026, the Company announced today that none of its 9,629,913 currently outstanding Cumulative Redeemable Rate Reset First Preferred Sha

Department of Energy Mandates Centralia Unit 2 Remain Available for Operation for Additional 90 Days

EXHIBIT 99.1 Department of Energy Mandates Centralia Unit 2 Remain Available for Operation for Additional 90 Days CALGARY, Alberta, March 17, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) confirms that its subsidiary, TransAlta Centralia Generation LLC, has received an order (The Order) from the United States Department of Energy. The Order mandates

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta Corporation Provides Conversion Right and Dividend Rate Notice for Series A and B Preferred Shares

EXHIBIT 99.1 TransAlta Corporation Provides Conversion Right and Dividend Rate Notice for Series A and B Preferred Shares CALGARY, Alberta, March 02, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) announced today that it does not intend to exercise its right to redeem all or any portion of the currently outstanding Cumulative Redeemable Rate Reset Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

TRANSALTA CORPORATION

Exhibit 97 TRANSALTA CORPORATION EXECUTIVE COMPENSATION CLAWBACK POLICY Introduction In accordance with the applicable rules of The New York Stock Exchange Listed Company Manual (the “Listing Standards”), Section 10D and Rule 10D-1 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), the Board of Directors (the “Board”) of TransAlta Corporation (the “Company”) has adopted this Policy (the “Policy”) to provide for the recoupment of erroneously awarded incentive-based compensation from Covered Executives (as defined below) in the event of an accounting restatement resulting from material noncompliance with financial reporting requirements under applicable securities laws.

Certifications

Exhibit 99.7 Certifications I, Joel Hunter, certify that: 1.I have reviewed this annual report on Form 40-F of TransAlta Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to

Year ended Dec. 31, 2025

Consolidated Financial Statements Management's Report To the Shareholders of TransAlta Corporation The Consolidated Financial Statements and other financial information included in the Annual Report have been prepared by management.

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 99.9 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Annual Report of TransAlta Corporation (the “Company”) on Form 40-F for the year ended Dec. 31, 2025, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Joel Hunter, Executive Vice President, Finance and C

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 99.8 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Annual Report of TransAlta Corporation (the “Company”) on Form 40-F for the year ended Dec. 31, 2025, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, John H. Kousinioris, President and Chief Executive O

Energy Transition(2)

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (MD&A) contains forward-looking statements.

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.5 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the reference of our Firm under the caption “Experts”, and to the incorporation by reference in the following Registration Statements: (1) Form S-8 Nos. 333-260935, 333-236894 pertaining to TransAlta Corporation’s Share Unit Plan, and Form S-8 Nos. 333-72454 and 333-101470 pertaining to TransAlta Corporation’s Shar

TransAlta to Host Investor Day

EXHIBIT 99.1 TransAlta to Host Investor Day CALGARY, Alberta, Feb. 27, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) is pleased to announce that it will hold an Investor Day in Toronto on Monday, March 23, 2026. The formal presentation will commence at 9:00 a.m. During the event, we will provide an in-depth overview of the Company’s strategic priori

TransAlta Enters Memorandum of Understanding for Data Centre Development at Keephills Site with Potential to Scale Up to 1 GW

EXHIBIT 99.1 TransAlta Enters Memorandum of Understanding for Data Centre Development at Keephills Site with Potential to Scale Up to 1 GW CALGARY, Alberta, Feb. 27, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TSX: TA) (NYSE: TAC) (TransAlta or the Company) is pleased to announce that it has entered into a Memorandum of Understanding (MOU) with Canada Pension Plan Investment Board (CPP Investme

Certifications

Exhibit 99.6 Certifications I, John H. Kousinioris, certify that: 1.I have reviewed this annual report on Form 40-F of TransAlta Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with res

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F [Check one] ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended Dec. 31, 2025 Commission file number 001-15214 TRANSALTA CORPORATION (Exact name of Registrant as sp

Series of First Preferred Shares

Table of Contents 2 Presentation of Information 2 Forward-Looking Statements 4 Corporate Structure 5 General Development of the Business 9 Business of TransAlta 19 Risk Factors 19 Dividends 19 Capital Structure 25 Credit Ratings 27 Market for Securities 29 Directors and Officers 34 Legal Proceedings and Regulatory Actions 35 Interests of Management and Others in Material Transactions 35 Transfer Agent and Registrar 35 Material Contracts 36 Interests of Experts 36 Annual Confirmation 36 Additional Information 36 Audit, Finance and Risk Committee A-1 Audit, Finance and Risk Committee Charter B-1 Glossary of Terms TransAlta Corporation • Annual Information Form 1 Presentation of Information This Annual Information Form (AIF) is dated Feb.

Table of Contents 2 President’s Message 4 Message from the Chairman of the Board M1 Management’s Discussion and Analysis F1 Consolidated Financial Statements F14 Notes to Consolidated Financial Statements 185 Plant Summary 188 Shareholder Information

a2025annualreport Table of Contents 2 President’s Message 4 Message from the Chairman of the Board M1 Management’s Discussion and Analysis F1 Consolidated Financial Statements F14 Notes to Consolidated Financial Statements 185 Plant Summary 188 Shareholder Information 192 Shareholder Highlights 193 Fighting Against Forced Labour and Child Labour in Supply Chains Act 199 Corporate Information 200 Glossary of Key Terms TransAlta Corporation 2025 Integrated Report 1 Letter from the President and CEO John H.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

Three Months Ended

News Release TransAlta Reports Fourth Quarter and Year End 2025 Results, Announces Data Centre Agreement, Declares Dividend Increase and Provides 2026 Outlook CALGARY, Alberta (February 27, 2026) TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) today reported its financial results for the fourth quarter and year ended Dec.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

TransAlta to Host Fourth Quarter and Full Year 2025 Results Conference Call

EXHIBIT 99.1 TransAlta to Host Fourth Quarter and Full Year 2025 Results Conference Call CALGARY, Alberta, Jan. 27, 2026 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) will release its fourth quarter and full year 2025 results before markets open on Friday, February 27, 2026. A conference call and webcast to discuss the results as well as the Company’s 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of pr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address

SECOND SUPPLEMENTAL INDENTURE TRANSALTA CORPORATION THE BANK OF NEW YORK MELLON, as Trustee Dated as of DECEMBER 22, 2025

EX-99.1 Exhibit 99.1 SECOND SUPPLEMENTAL INDENTURE between TRANSALTA CORPORATION and THE BANK OF NEW YORK MELLON, as Trustee Dated as of DECEMBER 22, 2025 TABLE OF CONTENTS PAGE ARTICLE 1 THE SECURITIES Section 1.01. Designation of Securities; Establishment of Form 2 Section 1.02. Transfer and Exchange 4 Section 1.03. Amount 6 Section 1.04. Regular Interest 6 Section 1.05. Denominations 6 Section

TransAlta Provides Notice to Mothball Sheerness Unit 1

EXHIBIT 99.1 TransAlta Provides Notice to Mothball Sheerness Unit 1 CALGARY, Alberta, Dec. 18, 2025 (GLOBE NEWSWIRE) - Alberta Power (2000) Ltd., a subsidiary of TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC), provided notice to the Alberta Electric System Operator on December 18, 2025, that Sheerness Unit 1 will be temporarily mothballed effective April 1, 2026, for a peri

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

Department of Energy Mandates Centralia Unit 2 Remain Available for Operation for 90 Days

EXHIBIT 99.1 Department of Energy Mandates Centralia Unit 2 Remain Available for Operation for 90 Days CALGARY, Alberta, Dec. 17, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) confirms that its subsidiary, TransAlta Centralia Generation LLC, has received an order (the Order) from the United States Department of Energy. The Order mandates that Centra

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant’s name into English) Suite 1400, 1100—1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

EX-99.1 Exhibit 99.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the reference to our firm under the caption “Experts” in the Prospectus Supplement, dated December 11, 2025, to the Registration Statement (Form F-10) and related short form base shelf prospectus of TransAlta Corporation (the “Corporation”) for the offering of senior notes and to the inclusion therein of ou

TransAlta Corporation 5.875% Senior Notes due 2034 Underwriting Agreement

EX-99.1 Exhibit 99.1 Conformed Version TransAlta Corporation US$400,000,000 5.875% Senior Notes due 2034 Underwriting Agreement New York, New York December 11, 2025 RBC Capital Markets, LLC As Representative of the several Underwriters, c/o RBC Capital Markets, LLC 200 Vesey Street New York, New York 10281-8098 Ladies and Gentlemen: TransAlta Corporation, a corporation organized under the laws of

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, Dec. 12, 2025 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.065 per common share payable on April 1, 2026, to shareholders of record at the close of business on March 1, 2026. The Board of Directors also declared the following quarterly dividend on its Cumulati

New Issue December 11, 2025 5.875% Senior Notes due 2034 TRANSALTA CORPORATION

SUPPL Table of Contents Filed pursuant to General Instruction II.L. of Form F-10 File No. 333-292019 PROSPECTUS SUPPLEMENT (To the short form base shelf prospectus dated December 9, 2025) New Issue December 11, 2025 US$400,000,000 5.875% Senior Notes due 2034 TRANSALTA CORPORATION We are offering US$400,000,000 aggregate principal amount of 5.875% senior notes due 2034 (the “Notes”). The Notes wil

TransAlta Corporation Pricing Term Sheet

FWP Filed Pursuant to Rule 433 Registration No. 333-292019 December 11, 2025 TransAlta Corporation Pricing Term Sheet This pricing term sheet is qualified in its entirety by reference to the Preliminary Prospectus Supplement, dated December 11, 2025 (the “Preliminary Prospectus Supplement”). The information in this pricing term sheet supplements the Preliminary Prospectus Supplement and updates an

SUBJECT TO COMPLETION, DATED DECEMBER 11, 2025

SUPPL Table of Contents Filed pursuant to General Instruction II.L. of Form F-10 File No. 333-292019 Information contained herein is subject to completion or amendment. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. This preliminary prospectus supplement and the accompanying short form base shelf prospectus shall not constitute an

As filed with the Securities and Exchange Commission on December 9, 2025

F-10EF Table of Contents As filed with the Securities and Exchange Commission on December 9, 2025 Registration No.

Security Type

Calculation of Filing Fee Tables F-10 TRANSALTA CORP Table 1: Newly Registered Securities ☑Not Applicable Security Type Security Class Title Fee Calculation Rule or Instruction Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Fees to be Paid N/A N/A N/A N/A N/A N/A N/A N/A N/A Fees Previously Paid N/A N/A N/A N/A N/A N/A N/A N/A N/A Total Offering Amounts: $ 0.

TransAlta Signs Long-Term Agreement for 700 MW at Centralia Facility Enabling Coal to Natural Gas Conversion

EXHIBIT 99.1 TransAlta Signs Long-Term Agreement for 700 MW at Centralia Facility Enabling Coal to Natural Gas Conversion CALGARY, Alberta, Dec. 09, 2025 (GLOBE NEWSWIRE) - Highlights TransAlta to perform coal-to-gas conversion on its Centralia Unit 2 facility in Washington state, with a planned contracted capacity of 700 MW The converted facility will deliver reliable power to Puget Sound Energy

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM F-X APPOINTMENT OF AGENT FOR SERVICE OF PROCESS AND UNDERTAKING    A. Name of issuer or person filing (“Filer”): TransAlta Corporation    B. (1) This is (check one) ☒ origin

F-X UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM F-X APPOINTMENT OF AGENT FOR SERVICE OF PROCESS AND UNDERTAKING    A. Name of issuer or person filing (“Filer”): TransAlta Corporation    B. (1) This is (check one) ☒ original filing for the Filer ☐ amended filing for the Filer (2) Check following box if you are filing the Form F-X in paper in accordance with Regulati

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

EX-7.2 Exhibit 7.2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE ☐ CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) THE BANK OF NEW YORK MELLON (Exact name of trustee as specified in its charter) New York 13-51603

TransAlta to Acquire 310 MW Contracted Ontario Gas Portfolio for $95 Million

EXHIBIT 99.1 TransAlta to Acquire 310 MW Contracted Ontario Gas Portfolio for $95 Million CALGARY, Alberta, Nov. 17, 2025 (GLOBE NEWSWIRE) - Highlights Purchase price of $95 million, or approximately $306 per kilowatt (kW) Immediately accretive to free cash flow and cash yield upon closing with approximately 68% of the portfolio's gross margin contracted to 2031; attractive recontracting fundament

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

Three Months Ended

News Release TransAlta Reports Third Quarter 2025 Results CALGARY, Alberta (November 6, 2025) TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) today reported its financial results for the third quarter ended Sept.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

Potential change in fair value(1)

Condensed Consolidated Statements of (Loss) Earnings (in millions of Canadian dollars except where noted) 3 months ended Sept.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of p

TransAlta Announces President and CEO Succession

EXHIBIT 99.1 TransAlta Announces President and CEO Succession CALGARY, Alberta, Nov. 06, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) announced today that John Kousinioris, President and Chief Executive Officer and a Director of TransAlta, plans to retire effective April 30, 2026. Concurrent with this announcement, the Board of Directors (Board) ha

2025 Target(2)

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (MD&A) contains forward-looking statements.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of pr

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, Oct. 22, 2025 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.065 per common share payable on Jan. 1, 2026, to shareholders of record at the close of business on Dec. 1, 2025. The Board of Directors also declared the following quarterly dividend on its Cumulative

TransAlta to Host Third Quarter 2025 Results Conference Call

EXHIBIT 99.1 TransAlta to Host Third Quarter 2025 Results Conference Call CALGARY, Alberta, Oct. 08, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) will release its third quarter 2025 results before markets open on Thursday, November 6, 2025. A conference call and webcast to discuss the results will be held for investors, analysts, members of the med

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of pr

TransAlta to Host 2025 Investor Day

EXHIBIT 99.1 TransAlta to Host 2025 Investor Day CALGARY, Alberta, Sept. 18, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) is pleased to announce that it will hold an Investor Day in Toronto on Tuesday, November 18, 2025. The formal presentation will commence at 9:00 a.m. (ET) (7:00 a.m. MT) and is expected to conclude by approximately 11:30 a.m. (E

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of

TransAlta Reports Strong Second Quarter 2025 Results, Advancement of Strategic Priorities and Reaffirms Guidance

EXHIBIT 99.1 TransAlta Reports Strong Second Quarter 2025 Results, Advancement of Strategic Priorities and Reaffirms Guidance CALGARY, Alberta, Aug. 01, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) today reported its financial results for the second quarter ended June 30, 2025. “Our strong second quarter results illustrate the value of our diversif

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executiv

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-152

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of pri

Potential change in fair value(1)

Condensed Consolidated Statements of (Loss) Earnings (in millions of Canadian dollars except where noted) 3 months ended June 30 6 months ended June 30 Unaudited 2025 2024 2025 2024 Revenues (Note 3) 433 582 1,191 1,529 Fuel and purchased power (Note 4) 173 154 450 477 Carbon compliance (recovery) costs (Note 4) (74) (8) (25) 32 Gross margin 334 436 766 1,020 Operations, maintenance and administra

Wind & Solar(4)

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (MD&A) contains forward-looking statements.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of princ

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, July 29, 2025 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.065 per common share payable on Oct. 1, 2025, to shareholders of record at the close of business on Sept. 1, 2025. The Board of Directors also declared the following quarterly dividend on its Cumulativ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of princ

TransAlta to Host Second Quarter 2025 Results Conference Call

EXHIBIT 99.1 TransAlta to Host Second Quarter 2025 Results Conference Call CALGARY, Alberta, July 03, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta”) (TSX:TA)(NYSE:TAC) will release its second quarter 2025 results before markets open on Friday, August 1, 2025. A conference call and webcast to discuss the results will be held for investors, analysts, members of the media and other inter

TransAlta Renews Normal Course Issuer Bid

EXHIBIT 99.1 TransAlta Renews Normal Course Issuer Bid CALGARY, Alberta, May 27, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that the Toronto Stock Exchange (“TSX”) has accepted the notice filed by the Company to implement a normal course issuer bid (“NCIB”) for a portion of its common shares (“Common Shares”). Pursuant to the

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of princi

Fair value(1)

Condensed Consolidated Statements of Earnings (in millions of Canadian dollars except where noted) 3 months ended March 31 Unaudited 2025 2024 Revenues (Note 3) 758 947 Fuel and purchased power (Note 4) 277 323 Carbon compliance (Note 4) 49 40 Gross margin 432 584 Operations, maintenance and administration (Note 4) 173 134 Depreciation and amortization 146 124 Asset impairment charges (Note 5) 15

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of princi

TransAlta Reports First Quarter 2025 Results and Reaffirms Annual Guidance

EXHIBIT 99.1 TransAlta Reports First Quarter 2025 Results and Reaffirms Annual Guidance CALGARY, Alberta, May 07, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) today reported its financial results for the first quarter ended March 31, 2025. "Our business delivered strong operational performance across the fleet during the first quarter. While the Co

Thermal Generation

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (MD&A) contains forward-looking statements.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 TRANSALTA CORPORATION (Translation of registrant’s name into English) 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive offices) Indicate by che

TransAlta Corporation Announces Results of the 2025 Annual and Special Meeting of Shareholders and Election of all Directors

EXHIBIT 99.1 TransAlta Corporation Announces Results of the 2025 Annual and Special Meeting of Shareholders and Election of all Directors CALGARY, Alberta, April 24, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TSX: TA) (NYSE: TAC) ("TransAlta" or the "Company") held its Annual and Special Meeting of Shareholders (“the Meeting”) on April 24, 2025. The total number of common shares represented by

TRANSALTA CORPORATION (the “Corporation”) Annual and Special Meeting of Shareholders (the “Meeting”) April 24, 2025 REPORT OF VOTING RESULTS NI 51-102 – Continuous Disclosure Obligations, Section 11.3 Matters Voted Upon

Exhibit 99.1 TRANSALTA CORPORATION (the “Corporation”) Annual and Special Meeting of Shareholders (the “Meeting”) April 24, 2025 REPORT OF VOTING RESULTS NI 51-102 – Continuous Disclosure Obligations, Section 11.3 Matters Voted Upon The total number of common shares represented by shareholders present at the Meeting and by proxy was 188,962,557 representing 63.43% of the Corporation’s outstanding

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, April 23, 2025 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared the following quarterly dividend on its Cumulative Redeemable Rate Reset First Preferred Shares for the period starting from and including March 31, 2025, up to but excluding June 30, 2025: Preferred Shares TSX Stock Symbol Div

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta to Host Annual Meeting of Shareholders and First Quarter 2025 Results Conference Call

EXHIBIT 99.1 TransAlta to Host Annual Meeting of Shareholders and First Quarter 2025 Results Conference Call CALGARY, Alberta, April 08, 2025 (GLOBE NEWSWIRE) - 2025 Annual Meeting of TransAlta Corporation Shareholders On Thursday, April 24, 2025, TransAlta Corporation (“TransAlta”) (TSX: TA) (NYSE: TAC) will hold its annual meeting of shareholders at 11:30 a.m. Mountain Time (1:30 p.m. Eastern Ti

TRANSALTA CORPORATION as Issuer COMPUTERSHARE TRUST COMPANY OF CANADA as Trustee Dated as of March 24, 2025 Table of Contents

EXHIBIT 99.1 Execution Version TRANSALTA CORPORATION as Issuer AND COMPUTERSHARE TRUST COMPANY OF CANADA as Trustee INDENTURE Dated as of March 24, 2025 Table of Contents Page Article 1 DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION 1 Section 1.1 Definitions. 1 Section 1.2 Rules of Interpretation. 12 Section 1.3 Compliance Certificates and Opinions. 12 Section 1.4 Form of Documents Delive

TRANSALTA CORPORATION as Issuer COMPUTERSHARE TRUST COMPANY OF CANADA as Trustee FIRST SUPPLEMENTAL INDENTURE PROVIDING FOR THE ISSUE OF 5.625% SENIOR UNSECURED NOTES DUE 2032 Dated as of March 24, 2025 Table of Contents

EXHIBIT 99.2 Execution Version TRANSALTA CORPORATION as Issuer AND COMPUTERSHARE TRUST COMPANY OF CANADA as Trustee FIRST SUPPLEMENTAL INDENTURE PROVIDING FOR THE ISSUE OF 5.625% SENIOR UNSECURED NOTES DUE 2032 Dated as of March 24, 2025 Table of Contents Page Article 1 THE NOTES 1 Section 1.01 Designation of the Notes. 1 Section 1.02 Amount 1 Section 1.03 Regular Interest 2 Section 1.04 Defaulted

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 Commission File Number: 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

TransAlta Corporation Enters into Automatic Share Purchase Plan

EXHIBIT 99.1 TransAlta Corporation Enters into Automatic Share Purchase Plan CALGARY, Alberta, March 26, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that it has entered into an automatic share purchase plan (“ASPP”) with its broker in order to facilitate repurchases of TransAlta’s common shares (“Common Shares”) under the Compa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of prin

EX 99.4

EX 99.4 EX 99.4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive offices) Indicate

EX 99.1

EX 99.1 Notice of Annual and Special Meeting of Shareholders When: April 24, 2025 11:30 a.m. (Mountain Time) Where: Virtual-only meeting format https://meetings.lumiconnect.com/ 400-164-661-424 NOTICE IS HEREBY GIVEN that an annual and special meeting (the “Meeting”) of the holders of common shares (the “Shareholders”) of TransAlta Corporation ("TransAlta") will be held on April 24, 2025, at 11:30

Value of Compensation Received in 2024

Contents Letter and Invitation to Shareholders 1 Notice of Annual and Special Meeting of Shareholders 5 General Information 8 About Our Shareholder Meeting 9 Mailing and Availability of Proxy Circular and 2024 Integrated Report 10 How to Vote 12 Business of the Meeting 19 Item of Business 1: Election of Directors 19 Item of Business 2: Financial Statements 39 Item of Business 3: Reappointment of A

EX 99.3

EX 99.3 EX 99.3

TAC / TransAlta Corporation / MILLENNIUM MANAGEMENT LLC - EXHIBIT I JOINT FILING AGREEMENT

EXHIBIT I JOINT FILING AGREEMENT This will confirm the agreement by and among the undersigned that the Schedule 13G filed with the Securities and Exchange Commission on or about the date hereof with respect to the beneficial ownership by the undersigned of the Common Shares, no par value, of TransAlta Corporation will be filed on behalf of each of the persons and entities named below in accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2025 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indica

Year ended Dec. 31, 2024

Consolidated Financial Statements Management's Report To the Shareholders of TransAlta Corporation The Consolidated Financial Statements and other financial information included in this annual report have been prepared by management.

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.5 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the reference of our Firm under the caption “Experts”, and to the incorporation by reference in the following Registration Statements: (1) Form S-8 Nos. 333-260935, 333-236894 pertaining to TransAlta Corporation’s Share Unit Plan, and Form S-8 Nos. 333-72454 and 333-101470 pertaining to TransAlta Corporation’s Shar

Certifications

Exhibit 99.7 Certifications I, Joel Hunter, certify that: 1.I have reviewed this annual report on Form 40-F of TransAlta Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to

Contents 2 President’s Message 4 Message from the Chairman of the Board M1 Management’s Discussion and Analysis F1 Consolidated Financial Statements F14 Notes to Consolidated Financial Statements 267 Eleven-Year Financial and Statistical Summary 270

Contents 2 President’s Message 4 Message from the Chairman of the Board M1 Management’s Discussion and Analysis F1 Consolidated Financial Statements F14 Notes to Consolidated Financial Statements 267 Eleven-Year Financial and Statistical Summary 270 Plant Summary 273 Sustainability Performance Indicators 283 Independent Practitioner’s Assurance Report 287 Shareholder Information 291 Shareholder Highlights 292 Fighting Against Forced Labour and Child Labour in Supply Chains Act 298 Corporate Information 299 Glossary of Key Terms TransAlta Corporation 2024 Integrated Report 1 Letter from the President and CEO John H.

TRANSALTA CORPORATION

Exhibit 97 TRANSALTA CORPORATION EXECUTIVE COMPENSATION CLAWBACK POLICY Introduction In accordance with the applicable rules of The New York Stock Exchange Listed Company Manual (the “Listing Standards”), Section 10D and Rule 10D-1 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), the Board of Directors (the “Board”) of TransAlta Corporation (the “Company”) has adopted this Policy (the “Policy”) to provide for the recoupment of erroneously awarded incentive-based compensation from Covered Executives (as defined below) in the event of an accounting restatement resulting from material noncompliance with financial reporting requirements under applicable securities laws.

Adjusted EBITDA(1)

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (MD&A) contains forward-looking statements.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2025 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

A- 1

Contents 2 Presentation of Information 2 Forward-Looking Statements 4 Corporate Structure 6 General Development of the Business 9 Business of TransAlta 29 Environmental Risk Management 32 Risk Factors 32 Employees 33 Capital Structure 38 Credit Ratings 40 Dividends 41 Market for Securities 43 Directors and Officers 50 Interests of Management and Others in Material Transactions 50 Indebtedness of D

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 99.8 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Annual Report of TransAlta Corporation (the “Company”) on Form 40-F for the year ended December 31, 2024, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, John H. Kousinioris, President and Chief Executi

TransAlta Reports Strong 2024 Results, Announces Dividend Increase and 2025 Annual Guidance

EXHIBIT 99.1 TransAlta Reports Strong 2024 Results, Announces Dividend Increase and 2025 Annual Guidance CALGARY, Alberta, Feb. 20, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (TransAlta or the Company) (TSX: TA) (NYSE: TAC) today reported its financial results for the fourth quarter and year ended Dec. 31, 2024. “Our business delivered solid results within the upper range of our guidance, drive

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F [Check one] ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended Dec. 31, 2024 Commission file number 001-15214 TRANSALTA CORPORATION (Exact name of Registrant as sp

Certifications

Exhibit 99.6 Certifications I, John H. Kousinioris, certify that: 1.I have reviewed this annual report on Form 40-F of TransAlta Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with res

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 99.9 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Annual Report of TransAlta Corporation (the “Company”) on Form 40-F for the year ended December 31, 2024, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Joel Hunter, Executive Vice President, Finance a

POWER OF ATTORNEY

EX-99.1 2 ex991.htm EXHIBIT 99.1 Exhibit 99.1 POWER OF ATTORNEY KNOW ALL PERSONS that Royal Bank of Canada (“RBC”), a Canadian chartered bank under and governed by the provisions of the Bank Act, being S.C. 1991, c.46, as amended, by these presents makes, constitutes and appoints each of Sherry Coulter, Terry Fallon, Lori Messer and Thomas Murphy, acting individually, its true and lawful attorney-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2025 Commission File Number: 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2025 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicat

TransAlta to Host Fourth Quarter and Full Year 2024 Results Conference Call

EXHIBIT 99.1 TransAlta to Host Fourth Quarter and Full Year 2024 Results Conference Call CALGARY, Alberta, Jan. 16, 2025 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta”) (TSX:TA)(NYSE:TAC) will release its fourth quarter and full year 2024 results before markets open on Thursday, February 20, 2025. A conference call and webcast to discuss the results will be held for investors, analysts, mem

SCHEDULE II BAM CLASS B PARTNERS INC.

Exhibit 99.2 SCHEDULE II BAM CLASS B PARTNERS INC. Name and Position of Officer or Director Principal Business Address Principal Occupation or Employment Citizenship Jack L. Cockwell, Director and Vice President 181 Bay Street, IN200, P.O Box 830, Toronto, Ontario M5J 2T3, Canada Chair of Brookfield Partners Foundation Canada Bruce Flatt, Director and Vice President 181 Bay Street, Suite 100, Toro

SCHEDULE IV BROOKFIELD INFRASTRUCTURE GROUP LIMITED

Exhibit 99.4 SCHEDULE IV BROOKFIELD INFRASTRUCTURE GROUP LIMITED Name and Position of Officer or Director Principal Business Address Principal Occupation or Employment Citizenship Chloe Berry, Director and Senior Vice President 181 Bay Street, Suite 100, Toronto, Ontario M5J 2T3, Canada Managing Director, Brookfield Infrastructure Partners L.P. Canada Carl Ching, Senior Vice President 181 Bay Stre

SCHEDULE V TRADING IN COMMON SHARES

Exhibit 99.5 SCHEDULE V TRADING IN COMMON SHARES The table below sets forth all transactions in the Common Shares effected by the Reporting Persons during the past 60 days. Party Trade Date Buy/Sell Number of Shares Weighted Average Price (C$) Low Price per Share (C$) High Price per Share (C$) BIF IV Eagle NR Carry LP 12/18/2024 Buy* 3,150 — — — Eagle Canada Common Holdings LP 12/18/2024 Buy* 1,95

SCHEDULE III BIF IV CDN GP LTD.

Exhibit 99.3 SCHEDULE III BIF IV CDN GP LTD. Name and Position of Officer or Director Principal Business Address Principal Occupation or Employment Citizenship Chloe Berry, Director and Senior Vice President 181 Bay Street, Suite 100, Toronto, Ontario M5J 2T3, Canada Managing Director, Brookfield Infrastructure Partners L.P. Canada Carl Ching, Senior Vice President 181 Bay Street, Suite 100, Toron

SCHEDULE I BROOKFIELD CORPORATION

Exhibit 99.1 SCHEDULE I BROOKFIELD CORPORATION Name and Position of Officer or Director Principal Business Address Principal Occupation or Employment Citizenship M. Elyse Allan, Director 181 Bay Street, Suite 100, Toronto, Ontario, M5J 2T3, Canada Corporate Director Canada and U.S.A. Jeffrey M. Blidner, Director 181 Bay Street, Suite 100, Toronto, Ontario, M5J 2T3, Canada Vice Chair, Brookfield Co

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, Dec. 09, 2024 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.06 per common share payable on April 1, 2025, to shareholders of record at the close of business on March 1, 2025. The Board of Directors also declared the following quarterly dividend on its Cumulativ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2024 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indica

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2024 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indica

TransAlta Closes Acquisition of Heartland Generation

EXHIBIT 99.1 TransAlta Closes Acquisition of Heartland Generation CALGARY, Alberta, Dec. 04, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (TSX: TA; NYSE: TAC) ("TransAlta" or "Company") announced today that it has completed its acquisition of Heartland Generation Ltd. and Alberta Power (2000) Ltd. (collectively, "Heartland") from Energy Capital Partners ("ECP"). The acquisition, which includes He

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indica

TransAlta to Acquire Heartland Generation from Energy Capital Partners at a Reduced Price of $542 Million

EXHIBIT 99.1 TransAlta to Acquire Heartland Generation from Energy Capital Partners at a Reduced Price of $542 Million CALGARY, Alberta, Nov. 14, 2024 (GLOBE NEWSWIRE) - Highlights TransAlta and ECP have agreed to an $80 million purchase price reduction to reflect two required asset divestitures representing 97 MW (net ownership) Transaction revalued at approximately $542 million, inclusive of the

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indica

$1.47 - $1.96

TRANSALTA CORPORATION Management’s Discussion and Analysis Third Quarter Report for 2024 This Management’s Discussion and Analysis (“MD&A”) contains forward-looking statements.

3 months ended Sept. 30

Condensed Consolidated Statements of Earnings (Loss) (in millions of Canadian dollars except where noted) 3 months ended Sept.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

TransAlta Reports Strong Third Quarter 2024 Results

EXHIBIT 99.1 TransAlta Reports Strong Third Quarter 2024 Results CALGARY, Alberta, Nov. 05, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) today reported its financial results for the three and nine months ended Sept. 30, 2024, demonstrating another quarter of strong financial performance. "Our third quarter results illustrate the value of our pr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2024 Commission File Number: 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicat

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, Oct. 23, 2024 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.06 per common share payable on January 1, 2025, to shareholders of record at the close of business on December 1, 2024. The Board of Directors also declared the following quarterly dividend on its Cumu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2024 Commission File Number: 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicat

Media Advisory: TransAlta Third Quarter 2024 Results and Conference Call

EXHIBIT 99.1 Media Advisory: TransAlta Third Quarter 2024 Results and Conference Call CALGARY, Alberta, Oct. 04, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta”) (TSX: TA) (NYSE: TAC) will release its third quarter 2024 results before markets open on Tuesday, November 5, 2024. A conference call and webcast to discuss the results will be held for investors, analysts, members of the media

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indic

TransAlta Announces Conversion Results for Series G and Series H Preferred Shares

EXHIBIT 99.1 TransAlta Announces Conversion Results for Series G and Series H Preferred Shares CALGARY, Alberta, Sept. 17, 2024 (GLOBE NEWSWIRE) - Further to TransAlta Corporation's (“TransAlta” or the “Company”) (TSX: TA; NYSE: TAC) press release dated August 22, 2024, the Company announced today that after taking into account all election notices received for the conversion of the Cumulative Red

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indic

TransAlta Announces Dividend Rates on Series G Preferred Shares and Series H Preferred Shares

EXHIBIT 99.1 TransAlta Announces Dividend Rates on Series G Preferred Shares and Series H Preferred Shares CALGARY, Alberta, Sept. 03, 2024 (GLOBE NEWSWIRE) - Further to the news release of TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA; NYSE: TAC) dated August 22, 2024, the Company announced today the applicable dividend rates for its cumulative redeemable rate reset first preferre

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 Commission File Number: 001-152

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate

TransAlta Provides Notice of Series G Preferred Shares Conversion Right

EXHIBIT 99.1 TransAlta Provides Notice of Series G Preferred Shares Conversion Right CALGARY, Alberta, Aug. 22, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA; NYSE: TAC) announced today that it does not intend to exercise its right to redeem all or any part of the currently outstanding cumulative redeemable rate reset first preferred shares Series G (“Series

$1.47 - $1.96

TRANSALTA CORPORATION Management’s Discussion and Analysis Second Quarter Report for 2024 This Management’s Discussion and Analysis (“MD&A”) contains forward-looking statements.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 Commission File Number: 001-152

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate

TransAlta Reports Second Quarter 2024 Results

EXHIBIT 99.1 TransAlta Reports Second Quarter 2024 Results CALGARY, Alberta, Aug. 01, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) today reported its financial results for the three and six months ended June 30, 2024, demonstrating strong financial performance and reaffirming its 2024 outlook. Second Quarter 2024 Financial Highlights TransAlta’

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executiv

6 months ended June 30, 2024

Condensed Consolidated Statements of Earnings (in millions of Canadian dollars except where noted) 3 months ended June 30 6 months ended June 30 Unaudited 2024 2023 2024 2023 Revenues (Note 3) 582 625 1,529 1,714 Fuel and purchased power (Note 4) 154 188 477 513 Carbon compliance (Note 4) (8) 25 32 57 Gross margin 436 412 1,020 1,144 Operations, maintenance and administration (Note 4) 144 134 278

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, July 29, 2024 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.06 per common share payable on October 1, 2024, to shareholders of record at the close of business on September 1, 2024. The Board of Directors also declared the following quarterly dividend on its Cum

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2024 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate b

Media Advisory: TransAlta Second Quarter 2024 Results and Conference Call

EXHIBIT 99.1 Media Advisory: TransAlta Second Quarter 2024 Results and Conference Call CALGARY, Alberta, July 04, 2024 (GLOBE NEWSWIRE) - TransAlta will release its second quarter 2024 results before markets open on Thursday, August 1, 2024. A conference call and webcast to discuss the results will be held for investors, analysts, members of the media and other interested parties the same day begi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2024 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate b

TransAlta Corporation Enters into Automatic Share Purchase Plan

EXHIBIT 99.1 TransAlta Corporation Enters into Automatic Share Purchase Plan CALGARY, Alberta, June 24, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that it has entered into an automatic share purchase plan (“ASPP”) with its broker in order to facilitate repurchases of TransAlta’s common shares (“Common Shares”) under the Compan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2024 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate b

TransAlta Renews Normal Course Issuer Bid

EXHIBIT 99.1 TransAlta Renews Normal Course Issuer Bid CALGARY, Alberta, May 27, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that the Toronto Stock Exchange (“TSX”) has accepted the notice filed by the Company to implement a normal course issuer bid (“NCIB”) for a portion of its common shares (“Common Shares”). Pursuant to the

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate by

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate by

TransAlta Achieves Commercial Operation of 200 MW Horizon Hill Wind Facility, increasing its United States Renewables Fleet to over 1 GW

EXHIBIT 99.1 TransAlta Achieves Commercial Operation of 200 MW Horizon Hill Wind Facility, increasing its United States Renewables Fleet to over 1 GW CALGARY, Alberta, May 21, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that the 200 MW Horizon Hill Wind Project ("Horizon Hill"), located in Logan County, Oklahoma, has achieved c

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number: 001-15214

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate by

TransAlta Reports First Quarter 2024 Results

EXHIBIT 99.1 TransAlta Reports First Quarter 2024 Results CALGARY, Alberta, May 03, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) today reported its financial results for the first quarter ended March 31, 2024, demonstrating strong operational and financial performance and reaffirming its 2024 outlook. First Quarter 2024 Financial Highlights Tra

3 months ended March 31, 2024

Condensed Consolidated Statements of Earnings (in millions of Canadian dollars except where noted) 3 months ended March 31 Unaudited 2024 2023 Revenues (Note 3) 947 1,089 Fuel and purchased power (Note 4) 323 325 Carbon compliance (Note 4) 40 32 Gross margin 584 732 Operations, maintenance and administration (Note 4) 134 124 Depreciation and amortization 124 176 Asset impairment charges (reversals

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive o

3 months ended March 31

TRANSALTA CORPORATION Management’s Discussion and Analysis First Quarter Report for 2024 This Management’s Discussion and Analysis (“MD&A”) contains forward-looking statements.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 TRANSALTA CORPORATION (Translation of registrant’s name into English) 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive offices) Indicate by che

TRANSALTA CORPORATION (the “Corporation”) Annual Meeting of Shareholders (the “Meeting”) April 25, 2024 REPORT OF VOTING RESULTS NI 51-102 – Continuous Disclosure Obligations, Section 11.3 Matters Voted Upon

Exhibit 99.1 TRANSALTA CORPORATION (the “Corporation”) Annual Meeting of Shareholders (the “Meeting”) April 25, 2024 REPORT OF VOTING RESULTS NI 51-102 – Continuous Disclosure Obligations, Section 11.3 Matters Voted Upon The total number of common shares represented by shareholders present at the Meeting and by proxy was 194,587,285 representing 63.21% of the Corporation’s outstanding common share

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate

TransAlta Corporation Announces Results of the Annual Meeting of Shareholders and Election of all Directors

EXHIBIT 99.1 TransAlta Corporation Announces Results of the Annual Meeting of Shareholders and Election of all Directors CALGARY, Alberta, April 25, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (TSX: TA) (NYSE: TAC) ("TransAlta" or the "Company") held its Annual Meeting of Shareholders (“the Meeting”) on April 25, 2024. The total number of common shares represented by shareholders at the Meeting

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate

TransAlta Declares Dividends

EXHIBIT 99.1 TransAlta Declares Dividends CALGARY, Alberta, April 24, 2024 (GLOBE NEWSWIRE) - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.06 per common share payable on July 1, 2024 to shareholders of record at the close of business on June 1, 2024. The Board of Directors also declared the following quarterly dividend on its Cumulative

TransAlta Achieves Commercial Operation of 300 MW White Rock Project and Increases its US Renewables Fleet to 820 MW

EXHIBIT 99.1 TransAlta Achieves Commercial Operation of 300 MW White Rock Project and Increases its US Renewables Fleet to 820 MW CALGARY, Alberta, April 24, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that the combined 300 MW White Rock East and White Rock West wind facilities (“White Rock”), located in Caddo County, Oklahoma,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate

TransAlta Joins Other Water Licence Holders and the Alberta Government to collaborate on flow management on the Bow River System

EXHIBIT 99.1 TransAlta Joins Other Water Licence Holders and the Alberta Government to collaborate on flow management on the Bow River System CALGARY, Alberta, April 19, 2024 (GLOBE NEWSWIRE) - TransAlta Corporation (“TransAlta” or the “Company”) (TSX: TA) (NYSE: TAC) announced today that it has signed onto a voluntary water-sharing memorandum of understanding (“MOU”) with over thirty other water

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 Commission File Number: 001-15214 TransAlta Corporation (Translation of registrant's name into English) 1400, 1100 - 1st Street S.E. (Address of principal executive office) Indicate

First Quarter 2024 Conference Call: Webcast link: https://edge.media-server.com/mmc/p/bs6yync3

Exhibit 99.1 Media Advisory: TransAlta Annual Meeting of Shareholders and First Quarter 2024 Results and Conference Call CALGARY, AB, March 28, 2024 /CNW/ - 2024 Annual Meeting of TransAlta Corporation Shareholders On Thursday, April 25, 2024, TransAlta Corporation ("TransAlta") (TSX: TA) (NYSE: TAC) will hold its annual meeting of shareholders at 11:00 a.m. Mountain Time (1:00 p.m. ET) in a virtu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2024 Commission File Number 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 1400, 1100 1st Street S.E., Calgary, Alberta, Canada, T2G 1B1 (Address of prin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2024 Commission File Number 001-1521

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 1400, 1100 1st Street S.E., Calgary, Alberta, Canada, T2G 1B1 (Address of prin

TransAlta Corporation Enters into Automatic Share Purchase Plan

Exhibit 99.1 TransAlta Corporation Enters into Automatic Share Purchase Plan CALGARY, AB, March 22, 2024 /CNW/ - TransAlta Corporation ("TransAlta" or the "Company") (TSX: TA) (NYSE: TAC) announced today that it has entered into an automatic share purchase plan ("ASPP") with its broker in order to facilitate repurchases of TransAlta's common shares ("Common Shares") under the Company's previously

Shareholder Meeting Notice The resolutions to be voted on at the meeting are listed below along with the sections within the Management Proxy Circular where disclosure regarding the matter can be found. 1. Election of Directors - Electing twelve (12)

Exhibit 99.4 Have questions about this notice? Call the Toll Free Number below or scan the QR code to find out more Toll Free – 1-866 964-0492 www.computershare.com/ noticeandaccess Notice of Availability of Proxy Materials for TRANSALTA CORPORATION Annual General Meeting Meeting Date and Location: When: April 25, 2024 Where: Virtual-only meeting format via live audio Fold 11:00 am (Mountain Time)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2024 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive offices) Indicate

MR SAM SAMPLE Appointment of Proxyholder I/We being holder(s) of securities of TransAlta Corporation (the”Company”) hereby appoint: OR John P. Dielwart, Chair of the Board, or failing this person, John H. Kousinioris, President and Chief Executive Of

Exhibit 99.3 8th Floor, 100 University Avenue Toronto, Ontario M5J 2Y1 www.computershare.com Mr A Sample Designation (if any) Add1 Add2 add3 add4 add5 add6 000001 Security Class 123 Holder Account Number C1234567890 XXX Fold This proxy is solicited by and on behalf of Management of TransAlta Corporation. Notes 1. Every shareholder has the right to appoint some other person or company of their choi

Notice of Annual Meeting of Shareholders

Exhibit 99.1 Notice of Annual Meeting of Shareholders When: April 25, 2024 11:00 a.m. (Mountain Time) Where: Virtual-only meeting format web.lumiagm.com/471294222 NOTICE IS HEREBY GIVEN that an annual general meeting (the “Meeting”) of the holders (“Shareholders”) of common shares of TransAlta Corporation (“TransAlta”) will be held on April 25, 2024, at 11:00 a.m. (Mountain Time) in a virtual-only

UN SDG

Exhibit 99.2 Our Sustainability Journey TransAlta Corporation is committed to environmental, social and governance (“ESG”) leadership and long-term and sustainable value creation for our shareholders. We believe our ESG leadership will allow us to maintain our competitive advantage, build resilience in a decarbonizing world and support Canada’s goals under the Paris Agreement. See the “Environment

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

Fair value(1)

Consolidated Financial Statements Management's Report To the Shareholders of TransAlta Corporation The Consolidated Financial Statements and other financial information included in this annual report have been prepared by management.

TRANSALTA CORPORATION

Exhibit 97 TRANSALTA CORPORATION EXECUTIVE COMPENSATION CLAWBACK POLICY Introduction In accordance with the applicable rules of The New York Stock Exchange Listed Company Manual (the “Listing Standards”), Section 10D and Rule 10D-1 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), the Board of Directors (the “Board”) of TransAlta Corporation (the “Company”) has adopted this Policy (the “Policy”) to provide for the recoupment of erroneously awarded incentive-based compensation from Covered Executives (as defined below) in the event of an accounting restatement resulting from material noncompliance with financial reporting requirements under applicable securities laws.

A- 1

Contents 2 Presentation of Information 2 Special Note Regarding Forward-Looking Statements 4 Documents Incorporated by Reference 4 Corporate Structure 7 Overview 12 General Development of the Business 20 Business of TransAlta 42 Environmental Risk Management 46 Risk Factors 63 Employees 64 Capital and Loan Structure 79 Credit Ratings 82 Dividends 85 Market for Securities 92 Directors and Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F [Check one] ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended Dec. 31, 2023 Commission file number 001-15214 TRANSALTA CORPORATION (Exact name of Registrant as sp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2024 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February, 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 1400, 1100 1st Street S.E., Calgary, Alberta, Canada, T2G 1B1 (Address of p

Dial-in number - Full-Year and Fourth Quarter 2023 Conference Call Toll-free North American participants call: 1-888-664-6392

Exhibit 99.1 TransAlta Reports Full Year and Fourth Quarter 2023 Results and Announces Enhanced Share Repurchase Program CALGARY, AB, Feb. 23, 2024 /CNW/ - TransAlta Corporation ("TransAlta" or the "Company") (TSX: TA) (NYSE: TAC) today reported its financial results for the fourth quarter and year ended Dec. 31, 2023, which highlight another year of exceptional performance led by strong financial

Letter from the President and CEO John H. Kousinioris President and Chief Executive Officer Dear Fellow Shareholders, Across our sector, 2023 was marked by significant challenges, ranging from increasing geopolitical risks, high inflation and rising

Letter from the President and CEO John H. Kousinioris President and Chief Executive Officer Dear Fellow Shareholders, Across our sector, 2023 was marked by significant challenges, ranging from increasing geopolitical risks, high inflation and rising equipment and capital costs, to financial setbacks with key equipment suppliers and industry participants. In this environment, our industry is demand

Adjusted EBITDA(1)

TRANSALTA CORPORATION Management’s Discussion and Analysis This Management’s Discussion and Analysis (“MD&A”) contains forward-looking statements.

TAC / TransAlta Corporation / Marquard & Bahls AG - SC 13G/A Passive Investment

SC 13G/A 1 ef20020673sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* TransAlta Corporation (Name of Issuer) Common Shares (Title of Class of Securities) 89346D107 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to d

Fourth Quarter and Full Year 2023 Conference Call: Toll-free North American participants call: 1-888-664-6392 Webcast link: https://app.webinar.net/gAlG7Ma75oE

Exhibit 99.1 Media Advisory: TransAlta Fourth Quarter and Full Year 2023 Results and Conference Call CALGARY, AB, Jan. 22, 2024 /CNW/ - TransAlta Corporation ("TransAlta") (TSX: TA) (NYSE: TAC) will release its fourth quarter and full year 2023 results before markets open on Friday, February 23, 2024. A conference call and webcast to discuss the results will be held for investors, analysts, member

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January, 2024 Commission File Number 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January, 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2024 Commission File Number 001-152

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2024 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, Canada, T2G 1B1 (Addres

SUPPLIER CODE OF CONDUCT

Exhibit 99.1 SUPPLIER CODE OF CONDUCT PURPOSE AND SCOPE The Supplier Code of Conduct (the “Code”) sets out the principles and standards expected of suppliers, their employees and contractors (collectively, the “Suppliers”) to meet while in the provision of goods and/or services to TransAlta Corporation and its subsidiaries and affiliates (collectively, “TransAlta”). The Code is a representation of

TransAlta Corporation Enters into Automatic Share Purchase Plan

Exhibit 99.1 TransAlta Corporation Enters into Automatic Share Purchase Plan CALGARY, AB, Dec. 19, 2023 /CNW/ - TransAlta Corporation ("TransAlta" or the "Company") (TSX: TA) (NYSE: TAC) announced today that it has entered into an automatic share purchase plan ("ASPP") with its broker in order to facilitate repurchases of TransAlta's common shares ("Common Shares") under the Company's previously a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December, 2023 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P

TransAlta Declares Dividends

Exhibit 99.1 TransAlta Declares Dividends CALGARY, AB, Dec. 11, 2023 /CNW/ - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared the following quarterly dividend on its Cumulative Redeemable Rate Reset First Preferred Shares for the period starting from and including December 31, 2023, up to but excluding March 31, 2024: Preferred Shares TSX Stock Symbol Dividend Rate Di

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December, 2023 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P

TransAlta Announces Growth Targets to 2028, Financial Outlook for 2024 and Declares Dividend Increase of 9%

Exhibit 99.1 TransAlta Announces Growth Targets to 2028, Financial Outlook for 2024 and Declares Dividend Increase of 9% CALGARY, AB, Nov. 21, 2023 /CNW/ - Highlights Expanded growth targets to deliver up to 1.75 GW with a target investment of $3.5 billion by 2028 which will deliver annual EBITDA of $350 million Growth will focus on customer-centred renewables and storage through the execution of

TransAlta and BHP Announce Commercial Operation of Innovative Hybrid Renewables Facility to Power Remote Mining Operations in Western Australia

Exhibit 99.1 TransAlta and BHP Announce Commercial Operation of Innovative Hybrid Renewables Facility to Power Remote Mining Operations in Western Australia CALGARY, AB, Nov. 22, 2023 /CNW/ - TransAlta Corporation ("TransAlta" or the "Company") (TSX: TA) (NYSE: TAC) and BHP Group Limited ("BHP") (NYSE: BHP) (ASX: BHP) announced today that the 48 MW Northern Goldfields solar and battery storage fac

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P

JOINT FILING AGREEMENT

EX-99.6 2 d286786dex996.htm EX-99.6 Exhibit 99.6 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including additional amendments thereto) with respect to the common shares, no par value, of TransAlta Corporation. This Joi

TAC / Transalta Corp. / BROOKFIELD ASSET MANAGEMENT INC. - SC 13D/A Activist Investment

SC 13D/A 1 d286786dsc13da.htm SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13D/A (Amendment No. 5) UNDER THE SECURITIES EXCHANGE ACT OF 1934 TransAlta Corporation (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 89346D107 (CUSIP Number) Swati Mandava Brookfield Corporation Brookfield Place 181 Bay Street, Suite 100 Toronto, On

Fair value(1)

CONSOLIDATED FINANCIAL STATEMENTS Condensed Consolidated Statements of Earnings (in millions of Canadian dollars except where noted) 3 months ended Sept.

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant’s name into English) Suite 1400, 1100 - 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal execut

LTA generation (GWh)(1)

MANAGEMENT'S DISCUSSION AND ANALYSIS TRANSALTA CORPORATION Management’s Discussion and Analysis Third Quarter Report for 2023 This Management’s Discussion and Analysis (“MD&A”) contains forward-looking statements.

Dial-in number - Third Quarter 2023 Conference Call Toll-free North American participants call: 1-888-664-6392

Exhibit 99.1 TransAlta Reports Third Quarter 2023 Results CALGARY, AB, Nov. 7, 2023 /CNW/ - Third Quarter 2023 Financial Highlights Earnings before income taxes of $453 million, an improvement of $327 million from the same period in 2022 Net earnings attributable to common shareholders of $372 million, an increase of $311 million from the same period in 2022 Cash flow from operating activities of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P

Dial-in number – TransAlta to Acquire Heartland Generation Toll-free North American participants call: 1-888-664-6392

Exhibit 99.1 TransAlta to Acquire Heartland Generation from Energy Capital Partners for $658 million - Expands Capabilities to Meet Demands of Energy Transition CALGARY, AB, Nov. 2, 2023 /CNW/ - Highlights Highly accretive to free cash flow and cash yield upon closing with approximately 55% of revenues contracted with a weighted-average remaining life of 16 years Transaction valued at approximatel

TransAlta Declares Dividends

Exhibit 99.1 TransAlta Declares Dividends CALGARY, AB, Oct. 30, 2023 /CNW/ - The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared a quarterly dividend of $0.055 per common share payable on January 1, 2024 to shareholders of record at the close of business on December 1, 2023. The Board of Directors also declared the following quarterly dividend on its Cumulative Redeemabl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2023 Commission File Number 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2023 Commission File Number 001-15

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2023 Commission File Number 001-15214 TRANSALTA CORPORATION (Translation of registrant's name into English) 110-12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, Canada, T2P 2

TransAlta to Host 2023 Investor Day

Exhibit 99.1 TransAlta to Host 2023 Investor Day CALGARY, AB, Oct. 19, 2023 /CNW/ - TransAlta Corporation (TSX: TA) (NYSE: TAC) ("TransAlta") is pleased to announce that it will hold an Investor Day in Toronto on Tuesday, November 21, 2023. The event will be a hybrid format, with in-person and live webcast attendance options available. The formal presentations will commence at 9:30 a.m. (ET) (7:30

Third Quarter 2023 Conference Call: Toll-free North American participants call: 1-888-664-6392 Webcast link: https://app.webinar.net/6okKz0o9jM0

Exhibit 99.1 Media Advisory: TransAlta Third Quarter 2023 Results and Conference Call CALGARY, AB, Oct. 11, 2023 /CNW/ - TransAlta Corporation ("TransAlta") (TSX: TA) (NYSE: TAC) will release its third quarter 2023 results before markets open on Tuesday, November 7, 2023. A conference call and webcast to discuss the results will be held for investors, analysts, members of the media and other inter