
As at (millions)	2022		2021
Accounts receivable – billed	$	223	$	213
Accounts receivable – unbilled	201		175
Other receivables	5		28
	429		416
Allowance for doubtful accounts	(1)		(2)
Total	$	428	$	414

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)	2022		2021
Customer accounts receivable – billed, net of allowance for doubtful accounts
Less than 30 days past billing date	$	154	$	162
30-60 days past billing date	44		39
61-90 days past billing date	12		3
More than 90 days past billing date	12		7
	222		211
Accounts receivable – unbilled	201		175
Other receivables	5		28
Total	$	428	$	414

We maintain allowances for lifetime expected credit losses related to doubtful accounts. Current 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.