Building a 13-week cash flow forecast your lender will believe

Thirteen weeks is a quarter: long enough to see a covenant test, a tax payment and a seasonal swing coming, short enough that every number can be tied to a real invoice, payroll or loan schedule. That is why lenders like it. It is also why a bad one is so easy to spot.

Start from cash, not from the P&L

A 13-week forecast is a direct forecast. It lists receipts and disbursements by week, starting from the actual bank balance on Monday morning. If your forecast starts from EBITDA and works backwards, it is a different report.

Pull opening balances from every account, including the ones in subsidiaries nobody thinks about. Then build receipts from open AR by expected pay date, not due date, using each customer's actual payment history.

Put the big fixed items in first

Payroll, rent, debt service and tax payments are known to the day. Enter them before anything else; they usually account for more than half of disbursements. Vendor payments come next, from open AP and your standard payment run schedule.

Measure your own variance

The forecast that earns trust is the one that reports its own misses. Every week, compare last week's forecast against what actually cleared the bank, by line. A variance under 5% on total receipts is good; a consistent miss in one direction tells you which assumption to fix.

Roll the forecast forward one week at a time and keep every version. When a lender asks why week 7 changed, you want to show them.