Accounts receivable

12 Months Ended

Dec. 31, 2024

Subclassifications of assets, liabilities and equities [abstract]

Accounts receivable

Accounts receivable

(a)Accounts receivable

As at (millions)	2024		2023
Accounts receivable – billed	$	194	$	278
Accounts receivable – unbilled	240		194
Other receivables	28		28
	462		500
Allowance for doubtful accounts	(8)		(2)
Total	$	454	$	498

The following table presents an analysis of the age of customer accounts receivable. Any late payment charges are levied at a negotiated rate on outstanding non-current customer account balances.

As at (millions)	2024		2023
Customer accounts receivable – billed, net of allowance for doubtful accounts
Less than 30 days past billing date	$	123	$	174
30-60 days past billing date	52		78
61-90 days past billing date	8		11
More than 90 days past billing date	3		13
	186		276
Accounts receivable – unbilled	240		194
Other receivables	28		28
Total	$	454	$	498

We maintain allowances for lifetime expected credit losses related to doubtful accounts. Economic conditions (including forward-looking macroeconomic data), historical information (including credit agency reports, if available), reasons for the accounts being past due and line of business from which the customer accounts receivable arose are all considered when determining whether to make allowances for past-due accounts. The same factors are considered when determining whether to write off amounts charged to the allowance for doubtful accounts against the customer accounts receivable. The doubtful accounts expense is calculated on a specific-identification basis for customer accounts receivable over a specific balance threshold and on a statistically derived allowance basis for the remainder. No customer accounts receivable balances are written off directly to bad debt expense.

The following table presents a summary of the activity related to our allowance for doubtful accounts:

Years Ended December 31 (millions)	2024		2023
Balance, beginning of year	$	2	$	1
Additions	6		1
Balance, end of year	$	8	$	2

Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments

The following table presents a summary of the activity related to our allowance for doubtful accounts:

Years Ended December 31 (millions)	2024		2023
Balance, beginning of year	$	2	$	1
Additions	6		1
Balance, end of year	$	8	$	2