Cash Flow Forecasting for Small Businesses: A Practical Guide

Profit on paper does not pay rent — cash does. A rolling cash flow forecast shows when money comes in and goes out, so you can spot shortages weeks before they become crises.

Start with what you know

List fixed outflows: rent, software subscriptions, loan repayments, and payroll. Add variable costs tied to revenue — materials, contractors, and VAT payments.

On the income side, use contracted revenue plus realistic pipeline estimates. Weight uncertain deals lower than signed contracts.

The 13-week rolling model

Finance teams at high-growth companies use 13-week forecasts because they are detailed enough to act on but short enough to stay accurate. Update weekly as invoices are paid and new expenses appear.

FinnAccountings AI CFO Agent builds this automatically from your bank feeds and recurring patterns, adjusting for seasonality and historical payment delays.

Scenario planning

Model a best case, base case, and downside (e.g. largest client pays 30 days late). Knowing your runway under each scenario informs hiring and investment decisions.

Red flags to watch

Growing revenue with shrinking cash usually means slow collections or rising costs. Watch days sales outstanding (DSO), VAT timing, and large annual renewals clustered in one month.