Accounts Receivable Aging & DSO
Measures how quickly a business collects payment from customers, and categorizes outstanding invoices by age to identify collection risks.
What It Tells You
Days Sales Outstanding (DSO) tells you the average number of days it takes your business to collect payment after a sale is made on credit. A lower DSO means you are collecting receivables faster, which improves cash flow and reduces the risk of bad debt.
When combined with an aging schedule that groups invoices into buckets by how many days past their due date, DSO gives you a complete picture of collection performance and potential trouble spots.
Components
- Accounts ReceivableThe total balance of outstanding invoices owed to the business by customers at the end of the measurement period.
- Total Credit SalesThe total revenue generated from credit sales (not cash sales) during the measurement period. Using total revenue instead will slightly understate DSO.
- Number of DaysThe number of days in the measurement period — typically 365 for annual, 90 for quarterly, or 30 for monthly analysis.
Aging Buckets
An AR aging report categorizes outstanding invoices into time-based buckets to highlight which receivables may become difficult to collect:
| Bucket | Days Outstanding | Risk Level |
|---|---|---|
| Current | 0 – 30 days | Low |
| 31 – 60 days | 31 – 60 days | Moderate |
| 61 – 90 days | 61 – 90 days | High |
| 90+ days | Over 90 days | Very High |
Invoices in the 90+ day bucket are the most likely to become bad debts. Many businesses increase their allowance for doubtful accounts as invoices age past 60 days.
Worked Example
Example: B2B Services Company (Annual)
On average, the company takes about 61 days to collect payment. If payment terms are net-30, this suggests invoices are being paid roughly one month late.
Why It Matters
Cash flow is the lifeblood of any business, and receivables are one of the biggest variables affecting it. A company can be profitable on paper but still face cash crunches if customers take too long to pay. DSO quantifies this risk in a single, trackable number.
Monitoring DSO month over month helps you catch collection slowdowns early. If DSO rises from 45 to 60 days over a quarter, it may be time to tighten credit policies, follow up on aging invoices more aggressively, or offer early payment discounts.
Industry benchmarks matter — a construction company might consider 60-day DSO normal, while a SaaS company billing monthly should aim for under 30. Comparing your DSO to peers and to your own stated payment terms is the most meaningful analysis.