Evrenus Fırat Polat · ·
A list of unpaid invoices tells you how much is owed. An aging report tells you something more useful: which of those invoices are newly late and probably fine, and which have been sitting for so long they need real attention now.
How an aging report is structured
Unpaid invoices are grouped into buckets based on how many days past due they are. Common buckets are 0-30, 31-60, 61-90, and 90+ days. Many reports also show a "current" column for invoices that are not yet due. Each bucket shows the total amount owed within it, giving you a shape at a glance: is most of what's owed recent (healthy) or is a growing share sitting in the 90+ bucket (a real warning sign)?
Some reports age from the invoice date instead of the due date. Aging from the due date is more useful for collection, since it shows how late each invoice really is. Pick one method and keep it.
Our AR aging calculator takes the totals for each bucket and works out what share of your total receivables each one represents. To check how many days late an individual invoice is, use the days past due calculator.
Worked example
Today is November 30. A studio has these unpaid invoices:
| Client | Invoice | Amount | Due date | Days past due | Bucket |
|---|---|---|---|---|---|
| Alpha | 1301 | $2,000 | Dec 10 | not due | Current |
| Beta | 1288 | $1,500 | Nov 20 | 10 | 0-30 |
| Gamma | 1275 | $3,000 | Nov 5 | 25 | 0-30 |
| Delta | 1250 | $1,200 | Oct 1 | 60 | 31-60 |
| Epsilon | 1190 | $2,800 | Aug 15 | 107 | 90+ |
Totals by bucket:
- Current: $2,000
- 0-30: $1,500 + $3,000 = $4,500
- 31-60: $1,200
- 61-90: $0
- 90+: $2,800
- Total unpaid: $10,500
Shares of the total: current 19%, 0-30 43%, 31-60 11%, 90+ 27%.
Reading it: $4,500 is recently late and likely just needs a reminder. But 27% of the balance is the single 90+ invoice from Epsilon. It is smaller in count but the biggest risk. Priority order: call Epsilon today, check what is blocking Delta, send routine reminders to Beta and Gamma. The aging view makes that obvious in seconds. A flat list sorted by amount would put Gamma first.
Why the buckets matter more than the total
A total "amount overdue" figure treats a payment that's 5 days late the same as one that's 5 months late, but those need completely different responses. A 5-day-late invoice usually just needs a routine reminder. A 5-month-late one has likely already been through normal follow-up without success, and needs a different approach. See collecting unpaid invoices.
Reading the shape, not just one number
A healthy aging report is weighted toward the current and 0-30 buckets, with amounts shrinking in each older bucket. That's a normal, expected flow of invoices moving from new to paid. A report where the 61-90 or 90+ buckets are large, or growing over time, signals a collections problem that isn't self-correcting and needs deliberate attention rather than routine follow-up.
Step by step: building one
- List all unpaid invoices with client, number, amount and due date.
- Choose your reporting date, usually today or month end.
- Calculate days past due for each (reporting date minus due date).
- Place each invoice in a bucket.
- Add up the totals by bucket and overall.
- Calculate each bucket's share of the total.
- Choose actions per bucket: reminder, call, letter, escalate.
- Save the report with its date so you can compare it next month.
Using it to prioritize
With limited time to chase overdue invoices, the aging report tells you where to start. Generally, work from the oldest and largest balances first, since they're both the most at risk of becoming uncollectible and the ones where the informal window for an easy resolution is closing. A small, recent overdue balance can usually wait a few more days for a routine reminder to work. A large, aging one can't.
Suggested actions by bucket:
- Current: nothing, or a pre-due note.
- 0-30: reminder (see invoice reminder templates).
- 31-60: direct call and a firmer message, check for disputes.
- 61-90: formal letter (see collection letter templates).
- 90+: decide: payment plan, agency, legal action or write-off. See bad debt.
Common mistakes
- Mixing aging from invoice date and from due date. The numbers will not be comparable.
- Leaving paid invoices on the list. Match payments first. See cash application.
- Ignoring disputed invoices. Mark them separately, and resolve them (see invoice disputes).
- Running it only once a quarter. By then old balances have hardened.
- Looking only at the total. The distribution is the story.
Run it regularly, not just when something feels wrong
Checking an aging report weekly or monthly, as a habit rather than a reaction, is what catches a growing 90+ bucket while it's still a handful of invoices. The alternative is discovering it once it's become a large, tangled backlog that takes real effort to work through. Pair it with DSO to see both the speed and the age of what's owed.
FAQ
How many buckets should I use?
Four or five is enough for most small businesses. More buckets add detail but also work.
Should I include invoices that are not yet due?
Yes, as a "current" column. It shows your full receivables and helps you see what is coming.
Can I make an aging report in a spreadsheet?
Yes. Columns for due date, amount and a formula for days past due are enough. Sort and filter by days.
When should I write off an invoice in the 90+ bucket?
There is no fixed rule. Review each one after your escalation steps. Local tax rules may also affect timing, so ask your accountant.