Company: TSLTF
Filing Date: 2025-12-12
Form Type: SUPPL
Source: 0001193125-25-317786
Chunk: 397

Company: TRANSALTA CORP
Filing Date: 2025-12-12
Form: SUPPL
Chunk 397
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| • |     | Certain assets that we own in Canada and 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. |

| • |     | Revenues from the Required Divestitures as they do not reflect ongoing business performance. |

Adjusted Fuel and Purchased Power Adjusted Fuel and Purchased Power is Fuel and Purchased Power (the most directly comparable IFRS measure) adjusted to exclude fuel and purchased power from the Required Divestitures as it does not reflect ongoing business performance.

| TransAlta Corporation |     | M55 |

Management’s Discussion and Analysis

Adjusted OM&A Adjusted OM&A is OM&A (the most directly comparable IFRS measure) adjusted to exclude:

| • |     | Acquisition-related transaction and restructuring costs, mainly comprised of severance, legal and 
 consultant fees as these do not reflect ongoing business performance.                             |

| • |     | ERP integration costs representing planning, design and implementation costs of upgrades to the                                             
 existing ERP system as they represent project costs that do not occur on a regular basis, and therefore do not reflect ongoing performance. |

| • |     | OM&A from the Required Divestitures as it does not reflect ongoing business performance. |

Adjusted Net Other Operating Income Adjusted Net Other Operating Income is Net Other Operating Income (the most directly comparable IFRS measure) adjusted to exclude insurance recoveries related to the Kent Hills replacement costs of the tower collapse as these relate to investing activities and are not reflective of ongoing business performance. Adjustments to Earnings (Loss) in Addition to Interest, Taxes, Depreciation and Amortization

| • |     | Fair value change in contingent consideration payable is not included as it is not reflective of 
 ongoing business performance.                                                                    |

| • |     | Asset impairment charges and reversals are not included as these are accounting adjustments that 
 impact depreciation and amortization and do not reflect ongoing business performance.            |

| • |     | Any gains or losses on asset sales or foreign exchange gains or losses are not included as these 
 are not part of operating income.                                                                |

Adjustments for Equity-Accounted Investments

| • |     | During the fourth quarter of 2020, we acquired a 49 per cent interest in the Skookumchuck wind                                                                                                                                                         
 facility,