How is the allowance for doubtful accounts calculated?
Direct answer: Most businesses estimate the allowance for doubtful accounts from their own collection history. A common approach groups open receivables by age, applies a higher expected-loss percentage to older aging buckets, and adds the results. A simpler approach applies one historical loss rate to total receivables. Under the U.S. expected-credit-loss standard (ASC 326, often called CECL), that historical experience is adjusted for current conditions and reasonable forecasts, and specific accounts known to be at risk can get their own reserve. The allowance is a contra-asset that reduces receivables to the amount expected to be collected, and increases to it are recorded as bad debt expense. For example, the Equifax Form 10-Q for the quarter ended September 30, 2026 says its allowance is based on historical write-off experience, the aging of outstanding receivables, customer payment patterns, specific reserves, and changes in economic conditions.
Aging-based example: if the current bucket holds most balances and carries a small loss percentage while the 90-plus-day bucket carries a much larger one, the allowance is the sum of each bucket balance times its percentage. The percentages should come from actual write-off history, reviewed each reporting period, not from a generic table.
The allowance is an estimate. Actual write-offs are charged against it later, and the estimate is trued up through bad debt expense when it proves too high or too low.