An aged debt (or aged receivables) report buckets outstanding invoices into bands — current, 1–30 days overdue, 31–60, 61–90 and 90+. It shows at a glance where to focus chasing effort.
The older the bucket, the less likely the money is to be paid, so the 30–60 day band is usually where effort pays off most.
Example
Current £4,000; 1–30 days £1,500; 31–60 days £900; 90+ days £300.