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Cash management

The 13-Week Cash Forecast: How to Stop Guessing About Cash

Cash surprises are rarely about profitability. They are about timing, and timing is forecastable nine weeks ahead.

5 min read

Cash flow surprises are rarely about profitability. They are about timing, and timing is forecastable.

The gap between profit and cash

A profitable month can consume cash. Inventory purchased ahead of a season, a deposit to a supplier, sixty-day customer terms against thirty-day supplier terms, a tax payment, a debt amortization. None of these appear on the income statement in the month they hit the bank.

The bank balance tells you where you are. It says nothing about where you will be in nine weeks, which is the horizon on which most avoidable cash problems form.

Why thirteen weeks

Thirteen weeks is one quarter, which is long enough to see a seasonal build or a large payment coming and short enough that the estimates are still credible. Beyond a quarter, weekly forecasting becomes guesswork. Inside a month, it is too late to do much about what you find.

What goes into it

The forecast is built forward from known commitments, not backward from historical averages. Collections modelled on actual customer payment behaviour rather than stated terms, because those differ and the difference is the point. Payroll by date, including bonus and commission timing. AP by due date from open invoices, not an average. Debt service, tax payments, and any deposits or capital commitments already made. Then revenue collections on a realistic conversion assumption.

The discipline that makes it work is comparing forecast to actual every week. A forecast nobody checks drifts within a month. One that is reconciled weekly gets more accurate, and the variances themselves teach you where your assumptions are wrong.

What it changes

The value is not the spreadsheet. It is that decisions move earlier. A hire gets delayed three weeks instead of reversed. A supplier conversation happens before the invoice is late. A credit line gets arranged while the numbers still look good, which is the only time it is easy to arrange.

A simple diagnostic

Ask what your cash position will be nine weeks from Friday. If the answer requires a guess, the forecast is the highest-return thing you could build this quarter.

Where does your finance function actually stand?

Eight questions on how your books run today. You get a score, a read on where you are fragile, and the order we would fix things in.