The aging report looks backward. Cash planning looks forward.

A snapshot of overdue balances, bucketed by delay.

An accounts-receivable aging report lists open invoices grouped by how far past due they are—current, 1–30 days, 31–60, 61–90, and beyond. It is a snapshot of the past due state of the ledger on the day you run it. Because it is generated from data every accounting system already holds, it is free, universal, and comparable across periods.

Its ubiquity is also why teams over-rely on it. When the aging report is the only receivables view, “collections strategy” quietly becomes “call whoever has been red the longest.”

Keep running it. It answers real questions.

1. Exposure. How much is outstanding, and how much of it is seriously overdue?
2. Deterioration. Is the 61–90 bucket growing quarter over quarter?
3. Provisioning. Older receivables are less likely to be recovered, which feeds bad-debt allowances and audit conversations.
4. Accountability. A shared, undisputed artifact for month-end review.

None of this should be replaced. The gap is elsewhere.

What the aging report cannot say.

First: it starts after the damage. An invoice appears in an overdue bucket only once it is already late. The most valuable interventions—confirming a payment date before the due date, catching a dispute while it is fresh—belong to a window the report does not cover.

Second: it treats all dollars in a bucket alike. A $500 invoice and a $50,000 invoice sit in the same 31–60 row. The report has no concept of which balance threatens payroll.

Third: it says nothing about when cash will actually arrive. “Current” does not mean “will pay on time.” A customer whose behavior has slipped still shows as current until the due date passes. For cash planning, the due date is a hope; the customer’s payment pattern is the evidence. With 47% of surveyed US small businesses reporting invoices more than 30 days overdue, the gap between due dates and real payment dates is the norm, not the exception. See Intuit’s 2025 late-payments survey.

Group the open balance by when it will likely settle.

The complementary view assigns each open invoice an expected payment date—due date plus that customer’s typical delay—and then groups the open balance by expected week. The output reads like a cash forecast built from behavior instead of promises:

This week: $38,000 expected · Next week: $61,000 expected, of which $24,000 sits on high-risk invoices · Already past expected date: $12,500

Two decisions become easier immediately. Collections: invoices already past their expected date (not just their due date) are genuinely stuck and deserve a person’s attention. Treasury: the weekly totals show whether enough cash is likely to land before the payroll run, while there is still time to act.

Start simple. Test anything smarter.

A defensible first version needs only closed-invoice history: for each customer, compute the median days from due date to payment date over the last year, and add it to each open invoice’s due date. A customer who typically pays 9 days late and owes an invoice due Friday has an expected payment date a week from Monday.

A statistical estimate can improve on this—weighting invoice size, terms, seasonality, and recent behavior changes—but only if it is tested honestly: train on older invoices, check on newer ones, and compare against the simple median rule. If the smarter estimate does not beat the simple rule on invoices it has never seen, use the simple rule.

A weekly rhythm that uses each view for what it is.

1. Monday: refresh both views. The aging report states exposure; the expected-date view states the plan.
2. Work the queue ranked by cash at risk, starting with invoices past their expected date.
3. Before Friday: confirm payment dates on high-risk invoices due next week—the cheapest collections action that exists.
4. Month-end: use the aging report for provisioning and trend review, as before.

The free PaidWhen workspace builds the forward-looking half from two CSV exports: a priority queue ranked by estimated cash at risk and a cash timeline grouped by expected payment week, with the estimate tested against your own newer invoices before it is trusted. Files never leave your browser.