What it means
In business, selling on credit is essential for winning customers, but it always brings the risk of non-payment. Under standard accounting rules, you cannot simply wait until a customer officially declares bankruptcy to recognise the loss.
Instead, you must use the allowance method to forecast unpaid bills and record an estimated bad debt expense proactively. This keeps your balance sheet accurate by showing a realistic value for your accounts receivable, preventing you from overstating what you actually expect to collect.
Why does this matter for non-finance managers? Because it directly affects your reported profits and asset values.
If you ignore potential defaults, your profit looks artificially high today, only to take a sudden hit later when unpaid bills pile up. By estimating these losses early, you follow the matching principle of accounting, which pairs revenues with the costs required to generate them, including the cost of uncollected credit.
In practice, businesses usually calculate this allowance using historical averages or by ageing their receivables. The ageing method looks at how long invoices have been overdue, applying higher risk percentages to older balances.
Once calculated, you create a contra-asset account called allowance for doubtful accounts, which sits right below your accounts receivable on the balance sheet to offset the total amount. When a specific customer finally proves unable to pay, you do not record a new expense.
Instead, you simply write off the specific balance against the cushion you already created. This keeps your financial reporting smooth, predictable, and compliant with standard accounting frameworks, giving leaders a clear view of their true cash position.
Imagine setting aside a small amount of cash each month for car repairs before something actually breaks, rather than waiting for a major breakdown to shock your bank account.
In practice
Real-world examples
Example 1
TechStart invoiced clients $10,000 this month, and past trends show that about 5% of its credit sales are never collected. Management estimates that $500 will not be paid, so it records a bad debt expense and a matching allowance of $500 immediately. The entry reduces reported profit this month, rather than in a later period when the non-payment finally becomes clear. This keeps monthly results aligned with the sales that generated them.
Example 2
BuildPro has $50,000 in outstanding customer invoices at the end of the quarter. Its ageing report shows that invoices overdue for several months carry a much higher risk of default, so the finance team applies higher percentages to those older balances. The result is an allowance of $2,500 for anticipated defaults this quarter. Leaders can see the expected loss at a glance and decide whether to tighten credit terms.
Example 3
Silverbrook Landscaping provides commercial services on credit worth $20,000 in the quarter. Management expects some retail clients may struggle through the winter months, so it sets an allowance of $1,000 for potential unpaid bills. The allowance does not mean any client has failed to pay yet. It simply recognises a realistic risk now, so the business is not caught out later.
Think of it
Imagine setting aside a small amount of cash each month for car repairs before something actually breaks, rather than waiting for a major breakdown to shock your bank account.
Formula
Calculation
Estimated Bad Debt = Total Credit Sales x Estimated Bad Debt Percentage. For example, if you have $100,000 in credit sales and your historical default rate is 3 percent, your calculation is $100,000 x 0.03 = $3,000 estimated bad debt expense.Case study
Seen in the real world
This is a fictional, illustrative scenario. BrightView Design, a growing digital agency, reached $200,000 in annual credit sales. Historically, about 4% of its billings went uncollected because of client cash flow problems. Using the allowance method, BrightView recorded an annual bad debt expense of $8,000 and set up a matching allowance for doubtful accounts on its balance sheet.
Mid-way through the year, a client owing $1,200 went out of business and could not pay. Instead of taking a sudden hit to that month's earnings, BrightView reduced its accounts receivable by $1,200 and cleared the write-off against its existing allowance account. Net income stayed steady and realistic, because the cost had already been recognised when the sales were made. The remaining allowance fell from $8,000 to $6,800, which the team reviewed at the end of the period.
At year end, the finance director compared the remaining allowance with the current ageing report. The review showed the balance was still a reasonable estimate, so the team adjusted it up slightly to reflect a larger share of overdue invoices. This routine check keeps the allowance honest. Many small businesses skip it until a loss arrives without warning.
Watch out
Common mistakes
- Waiting until a customer misses a payment before recording any expense.
- Using random guesswork instead of historical data to calculate the allowance percentage.
- Forgetting to subtract the allowance account from accounts receivable on the balance sheet.
Questions
People also ask
Is the allowance method the same as writing off an account?
No. The allowance is an estimate of future losses. A write-off happens later when you identify a specific customer who will definitely not pay.
Which financial statements are affected by the allowance method?
Both the income statement, where the bad debt expense reduces profit, and the balance sheet, where the allowance reduces accounts receivable.
Can small businesses just wait until tax time to handle unpaid bills?
No, standard accounting principles require you to match expenses to the period the sale occurred, which means estimating bad debts regularly.