The 13-week cash flow forecast is the most useful single report a growing business can keep. It shows, week by week for the next quarter, how much cash you will have and when it gets tight.
Why 13 weeks
Thirteen weeks is one quarter: long enough to see a problem coming and act, short enough to forecast with real data rather than guesses.
The structure
| Line | Week 1 | Week 2 | … | Week 13 |
|---|---|---|---|---|
| Opening cash | ||||
| Customer receipts | ||||
| Other receipts | ||||
| Payroll | ||||
| Suppliers | ||||
| Rent, loans, tax | ||||
| Closing cash |
Closing cash for one week is the opening cash for the next.
Building it
- Start with actual cash in every bank account today.
- Receipts: take open invoices and assign each to the week you expect to be paid, based on each customer's real payment habits, not their terms.
- Payments: list payroll dates, rent, loan payments, tax dates and supplier bills by due date.
- Add known one-offs: equipment, bonuses, annual insurance.
- Set a minimum cash level and flag any week that drops below it.
Keeping it useful
- Update it every week, replacing the forecast for the past week with actuals.
- Compare forecast to actual. Large gaps show where your assumptions are wrong.
- Use it to decide: delay a purchase, chase a customer, draw on a credit line.
Check how long your cash lasts with our free cash runway calculator.
Frequently asked questions
Weekly. Each week, replace last week with actual figures and add a new week at the end.
No. A budget plans profit for the year. The 13-week forecast tracks cash, week by week, for the next quarter.
