v3.25.3
Income taxes (Tables)
 12 Months Ended
Sep. 30, 2025
Income Taxes [Abstract]  
Disclosure of income tax expense
Year ended September 30
2025 2024
$ $
Current income tax expense
Current income tax expense in respect of the current year
 628,169  731,338 
Adjustments recognized in the current year in relation to the income tax (recovery) expense of prior
years
 (44,889) 12,998 
Total current income tax expense
 583,280  744,336 
Deferred income tax expense (recovery)
Deferred income tax recovery relating to the origination and reversal of temporary differences (33,531) (118,893)
Deferred income tax recovery relating to changes in tax rates (1,619) — 
Adjustments recognized in the current year in relation to the deferred income tax expense
  (recovery) of prior years
 35,775  (27,207)
Total deferred income tax expense (recovery) 625  (146,100)
Total income tax expense
 583,905  598,236 
Reconciliation of effective income tax rate from the combined federal and provincial canadian statutory tax rate
The Company’s effective income tax rate differs from the combined Federal and Provincial Canadian statutory tax rate as follows:
Year ended September 30
2025 2024
%
%
Company's statutory tax rate 26.5  26.5 
Effect of foreign tax rate differences (0.7) (0.3)
Final determination from agreements with tax authorities and expirations of statutes of limitations (0.4) (0.3)
Non-deductible and tax exempt items 0.5  0.3 
Recognition of previously unrecognized temporary differences —  (0.3)
Minimum income tax charge 0.2  0.2 
Changes in tax laws and rates (0.1) — 
Effective income tax rate 26.0  26.1 
Disclosure of continuity of deferred tax balance
The continuity schedule of deferred tax balances is as follows:
As at
September 30, 2024		 Additions
 from
business acquisitions		 Recognized in earnings Recognized
in other comprehensive income		 Recognized
in equity		 Foreign currency translation adjustment and other As at
September 30,
 2025
$ $ $ $ $ $ $
 Accounts payable, accrued
compensation and liabilities, provisions, and other long-term liabilities
 132,021  —  (13,894) —  (5,811) 3,933  116,249 
Tax benefits on losses carried
   forward		 51,180  —  618  —  —  2,164  53,962 
Retirement benefits obligations 27,034  —  2,297  (13,062) —  2,125  18,394 
Capitalized research and
   development 		174,467  —  18,545  —  —  5,370  198,382 
Lease liabilities 156,479  4,360  (712) —  —  7,925  168,052 
PP&E, contract costs,
intangible assets and other long-term assets
 (73,149) (44,860) (4,353) —  —  (4,801) (127,163)
Right-of-use assets (123,982) (4,360) 3,237  —  —  (6,800) (131,905)
Work in progress (15,621) —  (3,593) —  —  (857) (20,071)
Goodwill (93,682) —  (20,157) —  —  (2,949) (116,788)
Refundable tax credits on
   salaries		 (24,943) (532) 6,257  —  —  (25) (19,243)
Cash flow and net investment      hedges 14,060  —  26  5,873  —  294  20,253 
Other (2,429) —  11,103  (285) —  (900) 7,489 
Deferred taxes, net 221,435  (45,392) (626) (7,474) (5,811) 5,479  167,611 
As at September 30, 2023 Additions
from
business acquisitions		 Recognized in earnings Recognized
in other comprehensive income		 Recognized in equity Foreign currency translation
adjustment and
other		 As at
September 30,
2024
$ $ $ $ $ $ $
 Accounts payable, accrued
compensation and liabilities, provisions, and other long-term liabilities
 112,599  —  20,946  —  (3,599) 2,075  132,021 
Tax benefits on losses carried
forward		 56,078  —  (7,265) —  —  2,367  51,180 
Retirement benefits obligations 27,243  —  795  (356) —  (648) 27,034 
Capitalized research and
   development		 92,880  —  82,302  —  —  (715) 174,467 
Lease liabilities 169,288  —  (16,919) —  —  4,110  156,479 
PP&E, contract costs,
intangible assets and other long-term assets
 (123,717) —  49,457  —  —  1,111  (73,149)
Right-of-use assets (143,411) —  23,077  —  —  (3,648) (123,982)
Work in progress (14,372) —  (926) —  —  (323) (15,621)
Goodwill (87,259) —  (6,346) —  —  (77) (93,682)
Refundable tax credits on
salaries		 (22,568) —  (2,478) —  —  103  (24,943)
Cash flow and net investment     hedges (4,010) —  14,164  5,374  —  (1,468) 14,060 
Other 11,600  —  (10,707) (3,462) —  140  (2,429)
Deferred taxes, net 74,351  —  146,100  1,556  (3,599) 3,027  221,435 
16. Income taxes (continued)
The deferred tax balances are presented as follows in the consolidated balance sheets:
As at
September 30, 2025		 As at
September 30, 2024
$ $
Deferred tax assets 239,284  242,567 
Deferred tax liabilities (71,673) (21,132)
167,611  221,435