A business can be profitable on paper and still run out of cash, because a sale is not money until the customer pays. For most small businesses and freelancers, the gap between the two lives in one place: the list of invoices that have been sent but not paid.
An accounts receivable aging report turns that list into something you can act on. It sorts every unpaid invoice by how late it is, so you can see at a glance how much is overdue, who owes it, and which invoice to chase first. This guide explains how to read one, the one ratio worth tracking alongside it, and how to word reminders at each stage. The free Aged Receivables & Invoice Chaser builds the report from your invoices.
Key takeaways
- An aging report groups unpaid invoices by days past due: not yet due, 1–30, 31–60, 61–90 and over 90 days.
- The share of your receivables that is overdue, and how much sits in the older buckets, matters more than the total.
- Days sales outstanding = receivables ÷ credit sales for the period × days in the period. Compare it with your payment terms.
- Chase the oldest, largest invoices first, one conversation per client, and handle disputed invoices separately.
- Make each reminder a little firmer as an invoice ages, and always ask for a payment date.
What an aging report shows
Every invoice has a due date. On any given day, an unpaid invoice is either not yet due or a certain number of days past due. The aging report groups invoices into buckets by that number:
| Bucket | Meaning |
|---|---|
| Not yet due | Sent, but the payment terms have not run out |
| Due today | The last day of the terms |
| 1–30 days overdue | Usually an oversight, or a customer paying on their own schedule |
| 31–60 days overdue | A pattern is forming; a personal follow-up is needed |
| 61–90 days overdue | A problem; find out what is really going on |
| 90+ days overdue | At risk; escalate, and consider stopping further work |
A good report shows each bucket as an amount and as a percentage of everything outstanding, then breaks the same numbers down by client. Paid invoices drop out, partly paid invoices count only what is still owed, and disputed invoices are best shown on their own, because the next step for them is resolving the dispute, not a reminder.
A worked example
A small design studio runs its report at the end of September. It is owed 30,000 in total:
| Bucket | Amount | Share |
|---|---|---|
| Not yet due | 16,500 | 55% |
| 1–30 days overdue | 7,200 | 24% |
| 31–60 days overdue | 3,300 | 11% |
| 61–90 days overdue | 1,800 | 6% |
| 90+ days overdue | 1,200 | 4% |
| Total outstanding | 30,000 | 100% |
The headline is not the 30,000. It is that 13,500, or 45%, is overdue, and 3,000 of it is more than 60 days late. The 1–30 day bucket is normal friction. The two oldest buckets are where the risk lives, and they are small enough to fix this week with a few phone calls.
Now look at the same money by client. If one client owns most of the 61+ day amounts, that is one conversation to have, not five invoices to chase.
Days sales outstanding: the one ratio to track
Days sales outstanding (DSO) estimates how long, on average, it takes you to get paid:
DSO = accounts receivable ÷ credit sales in the period × days in the period
If the studio invoiced 75,000 over the last 90 days and is owed 30,000 today, its DSO is 30,000 ÷ 75,000 × 90 = 36 days. With 30-day payment terms, customers are paying about six days late on average. That is not alarming on its own. What matters is the trend: a DSO that creeps from 36 to 45 to 55 over three quarters means cash is getting stuck, even if every individual invoice looks explainable.
Who to chase first
- Set disputed invoices aside. A reminder for a disputed invoice irritates the client and changes nothing. Resolve the dispute, then invoice again if needed.
- Sort by age, then by amount. The oldest invoices are the hardest to collect, so they come first; among invoices of a similar age, the larger ones.
- Group by client. One conversation covering every open invoice for a client is better than three separate reminders.
- Check your own paperwork before you call: the right contact, the purchase order number, the correct amount. A surprising number of "late" invoices are stuck because something on the invoice was wrong.
What to say at each stage
The tone should rise gently with the age of the invoice. Every message should include the invoice number, the amount, and a request for a payment date, because a date is a commitment and "we'll look into it" is not.
- 1–30 days: "Hi Anna, just a quick reminder about invoice #1042 for 2,400, which is now overdue. Could you let me know when we can expect payment?"
- 31–60 days: "Hi Anna, following up on invoice #1042 for 2,400, which is still outstanding. Please confirm the expected payment date."
- 61–90 days: "Hi Anna, invoice #1042 for 2,400 remains overdue. Please confirm its current status and when it will be settled." This is the stage for a phone call as well as an email.
- 90+ days: "Hi Anna, invoice #1042 for 2,400 is now significantly overdue. Please confirm the payment status and settlement date as soon as possible." Decide, too, whether to pause further work until it is paid.
Stopping invoices from aging in the first place
- Agree the terms before the work, in writing, and put them on every invoice.
- Invoice promptly, the day the work is delivered or the milestone is met.
- Get the details right: the client's billing contact, their purchase order number, their company name exactly as registered.
- Send a friendly reminder a few days before the due date, not only after it.
- Ask new clients for a deposit, and bill larger projects in stages.
Build the report in the Aged Receivables tool
The free Aged Receivables & Invoice Chaser turns a list of invoices into the aging report above:
- Enter each invoice's number, client, invoice and due dates, amount, amount paid, status (unpaid, partly paid, paid or disputed), contact and notes, or import a CSV.
- It sorts every invoice into aging buckets as of the date you choose, with the amount and share in each, and totals by client.
- A needs follow-up list puts the overdue invoices in order, oldest first and then largest, leaving disputed invoices out.
- Each overdue invoice gets reminder wording that becomes firmer at 30, 60 and 90 days, ready to copy into an email.
- Download an Excel-compatible XLSX, or a recap image for a quick update to a partner or accountant.
Everything runs in your browser; nothing is uploaded. To see how receivables affect your bank balance over the next year, put the expected payments into the 12-Month Cash Flow Forecast, and read our guide to building a 12-month cash flow forecast.
Frequently asked questions
How often should I run an aging report?
Weekly works well for most small businesses, and at every month end. The point is to catch invoices as they move from one bucket to the next, while they are still easy to collect.
What is a good DSO?
It depends on your payment terms and your industry. A DSO close to your standard terms means customers are mostly paying on time. More useful than any benchmark is your own trend over several months.
Should disputed invoices be included?
Include them in the total you are owed, but track them separately. They need a conversation about the problem, not a payment reminder.
Is an aging report the same as a ledger?
No. The ledger records every transaction. The aging report is a view of the unpaid invoices only, grouped by how late they are, which is what you need to plan collections.
When should an invoice be written off?
That is a decision to make with your accountant, based on the facts of the debt and the rules that apply to your business. The aging report gives you the history they will ask for.