Why cash flow forecasting matters
Profit and cash flow are not the same thing. A business can be profitable on paper while simultaneously running out of cash. This happens when invoices are raised but not yet paid, stock is purchased ahead of sales, or when large one-off payments fall due in the same period.
A cash flow forecast surfaces these mismatches in advance, giving you time to arrange additional finance, delay a payment, or accelerate a collection before the shortfall arrives. Businesses that forecast consistently are better placed to manage growth, negotiate with suppliers, and access finance when they need it.
What to include in a cash flow forecast
A forecast covers all cash movements: money actually received and paid, not income and expenses on an accruals basis. The distinction matters because an invoice raised in January but paid in March only counts as cash income in March.
- Cash inflows: customer payments (not invoice dates), loan receipts, investment proceeds, asset sales, tax refunds
- Cash outflows: supplier payments, wages and PAYE/NIC, rent, loan repayments, VAT payments, corporation tax, capital expenditure
- Opening cash balance at the start of each period
- Closing cash balance (opening balance plus net cash movement)
Forecast horizons
A 13-week rolling forecast (quarterly, updated weekly) is widely considered best practice for operational cash management. For strategic planning purposes, an annual forecast broken into monthly periods provides longer-range visibility.
The most useful forecasts are reviewed and updated regularly against actuals. The variance between forecast and actual tells you a great deal about the reliability of your assumptions and the predictability of your business.
Using forecasts to access finance
Lenders and investors will expect to see a cash flow forecast as part of any finance application. A well-constructed, realistic forecast demonstrates management capability and gives the lender confidence in your ability to service a facility. If your forecast shows a cash shortfall at a specific point, it supports the case for an invoice finance or working capital facility to bridge that gap.
Worked Example
A service business with £80,000 monthly turnover on 45-day payment terms needs to forecast whether it can afford a £15,000 equipment purchase in month 3.
- Month 1: opening balance £12,000, expected cash receipts £65,000 (last month's invoices due), outgoings £58,000, closing balance £19,000
- Month 2: opening £19,000, receipts £70,000, outgoings £61,000, closing £28,000
- Month 3: opening £28,000, receipts £75,000, outgoings £62,000 plus £15,000 equipment = £77,000, closing £26,000
- The forecast shows the equipment purchase is affordable while maintaining a positive cash balance
The forecast confirms the purchase is viable. If the closing balance in month 3 had been negative, the business would know in advance to either delay the purchase, arrange asset finance, or accelerate collections.
Frequently Asked Questions
How far ahead should a cash flow forecast cover?
A 13-week rolling forecast is standard for operational management. Lenders typically want to see a 12-month monthly forecast as part of a finance application.
Is cash flow forecasting the same as profit forecasting?
No. A profit forecast (P&L projection) shows revenues and expenses on an accruals basis. A cash flow forecast shows actual cash received and paid. They will differ whenever there are timing differences between raising invoices and receiving payment.
What software can I use to build a cash flow forecast?
Xero, Sage, and QuickBooks all have cash flow forecasting features. Standalone tools like Float, Fluidly, or a well-structured Excel spreadsheet are also widely used.