Company: TSLTF
Filing Date: 2025-12-12
Form Type: SUPPL
Source: 0001193125-25-317786
Chunk: 226

Company: TRANSALTA CORP
Filing Date: 2025-12-12
Form: SUPPL
Chunk 226
---
 directly comparable IFRS measure is earnings before income taxes. The following are descriptions of the adjustments made. Adjustments to Revenue

| • |     | Adjusted EBITDA is adjusted to exclude the impact of unrealized mark-to-market gains or losses and unrealized foreign exchange gains or losses on commodity transactions. |

| • |     | Adjustments are made for gains and losses related to closed positions effectively settled by         
 offsetting positions with exchanges that have been recorded in the period the positions are settled. |

| • |     | Certain assets that we own in Canada and in Western Australia are fully contracted and recorded as                                                                                                                                             
 finance leases under IFRS. We believe that it is more appropriate to reflect the payments we receive under the contracts as a capacity payment in our revenues instead of as finance lease income and a decrease in finance lease receivables. |

| • |     | The Brazeau penalties are issued by the Alberta Market Surveillance Administrator for self-reported                                                                                                                                                 
 contraventions pertaining to Hydro ancillary services provided during 2021 and 2022. The penalties have been excluded and does not represent ongoing performance. In 2022 a provision of $20 million was initially recognized in revenue reflecting 
 a potential disgorgement of revenue and $2 million for potential penalties and fines. The final assessment contained no disgorgement of revenue and penalties of $33 million. This resulted in a reversal of the original disgorgement              
 provision in revenue in the year ended Dec. 31, 2024 and recognition of the full amount of the penalties assessed in OM&A.                                                                                                                          |

| • |     | Revenues from the Planned Divestitures are not included as they do not reflect ongoing business 
 performance.                                                                                    |

Adjustments to Fuel and Purchased Power

| • |     | On the commissioning of the South Hedland facility in July 2017, we prepaid approximately                                                                                                                                                          
 $74 million of electricity transmission and distribution costs. Interest income is recorded on the prepaid funds. We reclassify this interest income as a reduction in the transmission and distribution costs expensed each period to reflect the 
 net cost to the business.                                                                                                                                                                                                                          |

| M64 |     | TransAlta Corporation |     | 2024 Integrated Report |

Management’s Discussion and Analysis

| • |     | Fuel and purchased power from the Planned Divestitures is not included as it does not reflect 
 ongoing business performance.                                                                 |

Adjustments to OM&A

| • |     | Acquisition-related transaction and restructuring costs, mainly