What is 13-Week Cash Flow Forecast?
Short answer: A 13-week cash flow forecast is a rolling, direct-cash schedule for the next thirteen weeks. It shows when money is expected to enter and leave bank accounts. It differs from an accrual profit forecast because invoiced revenue and recognised expense may occur in different weeks from collection and payment.
Thirteen weeks is long enough to capture most quarterly payroll, rent, tax, debt-service and supplier cycles while remaining close enough to link material amounts to evidence. The forecast normally separates operating receipts, payroll, suppliers, tax, capital expenditure and financing. Available cash should exclude restricted balances and show undrawn facilities only when they are genuinely accessible. A minimum liquidity line makes pressure visible before the bank balance reaches zero. In a stressed situation, the schedule becomes a control process with named actions and frequent updates, not just a spreadsheet.
How it works
Begin with verified bank balances and reconcile them to the ledger. Populate customer receipts from invoices, ageing and collection owner estimates. Map payroll, tax, supplier payments, leases, debt service and committed projects to contractual dates. Distinguish committed, probable and discretionary flows. Show facility drawdowns, limits, conditions and repayment dates separately. Assign an owner and evidence date to every material assumption. Each week, replace forecast with actual, explain timing and permanent variances, roll the horizon forward and update actions. Model a base case and credible downside, including delayed collections and payments that cannot legally or commercially be deferred.
Closing available cash = opening available cash + receipts - payments + net financing movements
Example
Week 1 opens with available cash of 420. Customer receipts are 260, payroll is 190, suppliers are 210 and debt service is 60, so closing cash is 420 + 260 - 190 - 210 - 60 = 220. Week 2 then opens at 220, receives 180 and pays 250, closing at 150. If the board minimum is 200, the first breach is 50 in week 2. A downside delay of 100 of week 1 receipts would instead leave 120 in week 1 and 50 in week 2, identifying both timing and size of the required action.
Why it matters
Founders and CFOs use the forecast to sequence collections, spending and financing while there is time to act. Boards review the first breach, assumption ownership and contingency triggers. Lenders assess draw requirements, headroom and the credibility of remedial actions. Buyers use it to understand closing liquidity and immediate funding needs. Sellers can demonstrate control over cash during a process. Equity investors use the schedule to size bridge funding and test whether milestones can be reached before another raise.
The forecast is not assurance that cash will arrive. It can fail through optimistic collection dates, omitted liabilities, double-counted facilities or unauthorised payment delays. Directors must consider duties and solvency tests under applicable law, which a thirteen-week spreadsheet cannot determine. Restricted cash, lender conditions and group cash-pooling rules need legal and treasury review. When liquidity is constrained, obtain jurisdiction-specific restructuring, insolvency, tax and employment advice promptly.