A cash-flow forecast shows when money is expected to enter and leave your business, so you can act before a shortfall becomes a crisis. It is different from a profit-and-loss report. A profitable business can still struggle if customers pay late, VAT falls due, a large supplier bill lands or tax has not been reserved.
For small businesses in Cheltenham and Gloucestershire, a simple rolling forecast can make day-to-day decisions calmer. The same approach works for nationwide service businesses: use real payment dates, update the forecast regularly and focus on the weeks ahead rather than hoping the bank balance will look after itself.
What a cash-flow forecast tells you
A forecast starts with the money you actually have, then estimates when expected receipts and payments will move through the bank. It helps answer practical questions:
- Can we pay suppliers? See whether planned outgoings exceed available cash in a particular week or month.
- What will VAT cost? Estimate upcoming VAT, payroll and tax dates before they arrive.
- Which invoices need chasing? Identify when a late-paying customer will create pressure rather than simply waiting for the due date to pass.
- Can we invest? Test whether a purchase, new hire or marketing campaign is affordable without endangering working capital.
- When should we act? Create time to adjust spending, agree payment terms, chase debtors or discuss finance before cash is tight.
The British Business Bank’s cash-flow forecasting guidance is a useful external resource for the basic model. The important thing is to use your own realistic dates and assumptions.
Profit is not the same as cash
Profit measures whether income exceeds costs over a period. Cash flow tracks the timing of money moving through your bank account. The two can be very different.
For example, you may invoice a customer in March but receive payment in May. The sale may appear in your accounts before the cash arrives. At the same time, you may have to pay staff, suppliers, VAT or tax before the customer settles the invoice. A forecast makes that timing visible.
It also protects you from treating the current bank balance as spare money. Part of it may already be committed to upcoming liabilities. Our guide to preparing your first Corporation Tax bill explains why a tax reserve should be planned before the deadline is close.
Build a simple 13-week forecast
A 13-week forecast is a useful starting point for many small businesses. It is short enough to be realistic and long enough to show the next VAT, payroll or supplier pressure point. You can use a spreadsheet or your cloud accounting software, provided the figures are maintained.
| Line in the forecast | What to include |
|---|---|
| Opening bank balance | The actual reconciled cash at the start of the week. |
| Expected customer receipts | Invoices by realistic payment date, not simply by their invoice date. Allow for known slow payers. |
| Other cash in | Loans, grants, tax refunds, deposits or other receipts that are genuinely expected. |
| Supplier and overhead payments | Rent, software, stock, subcontractors, utilities, insurance, finance and other committed costs by payment date. |
| Tax and payroll | VAT, PAYE, pension contributions, Corporation Tax and personal drawings where they affect the business’s cash. |
| Closing bank balance | Opening cash plus receipts minus payments. This becomes the following week’s opening balance. |
Do not make the forecast complicated for the sake of it. Start with the big, known movements. You can add detail once the routine is working.
Use realistic payment dates
The quality of a forecast depends on the assumptions behind it. An invoice due in seven days is not necessarily cash due in seven days. If a customer usually pays two weeks late, use the expected payment date rather than the contractual one.
The same is true for your own spending. Include the date a Direct Debit leaves the bank, the payroll date, the VAT due date and the date a supplier actually collects payment. It is the timing that determines whether there is a shortfall.
Plan for tax before it becomes urgent
Tax payments are predictable enough to forecast even when the final amount will change. Build separate lines for VAT, PAYE, Corporation Tax and, where relevant, money you need to reserve for personal Self Assessment. The exact amount may be a forecast, but leaving it out entirely will make the cash position look better than it is.
If you are self-employed, remember that January can include both your balancing payment and the first payment on account for the following tax year. Read our guide to HMRC payments on account to understand why that date can create a sharp cash requirement.
Turn the forecast into decisions
The forecast only becomes valuable when it changes what you do. When you see a potential shortfall, you have options while there is still time:
- Chase invoices earlier. A polite, prompt reminder can bring forward a receipt and reduce the need for borrowing.
- Ask for deposits. For project work or larger orders, a deposit can help align cash in with the costs of delivering the job.
- Review payment terms. Avoid agreeing terms that leave you funding a client’s business from your own bank account.
- Delay non-essential spend. Move a discretionary purchase until the forecast shows the cash is genuinely available.
- Discuss finance early. If external finance is appropriate, conversations are stronger before the business is under pressure.
A forecast can also give you confidence to go ahead. If the numbers show that a new hire or investment is affordable after allowing for realistic timing and tax, you can make the decision on evidence rather than nerves.
Keep the forecast alive
A one-off forecast is useful. A rolling forecast is far more valuable. Update it weekly, replace estimates with actual receipts and payments, then roll the horizon forward. Compare what you expected with what actually happened and adjust the assumptions.
Cloud accounting can make this easier by keeping invoices, bank balances and bills visible in one place. Our guide to Xero cloud accounting for small businesses explains how live records support better financial decisions.
Common cash-flow forecasting mistakes
- Using sales dates. Forecast cash by when it is likely to arrive, not when the invoice was raised.
- Ignoring tax. VAT, PAYE and Corporation Tax are not optional future costs. Include them.
- Assuming every debtor pays. Allow for late payment, disputed invoices and a sensible level of uncertainty.
- Forgetting annual costs. Insurance renewals, software subscriptions, rent reviews and professional fees can create surprises if they are not scheduled.
- Mixing personal drawings. Directors should avoid using company cash informally. Our guide to director’s loan accounts and Section 455 explains why clear records matter.
Build a clearer cash plan for your business
SB Business Consulting helps owner-managed businesses use their accounts to make better decisions, not simply complete a year-end filing. I work with businesses in Cheltenham and across Gloucestershire, as well as nationwide through cloud systems. Explore our bookkeeping and Xero support and business advice and tax planning service.
This article is general guidance. A cash-flow forecast is only as reliable as the information and assumptions behind it. Update it regularly and obtain tailored advice before taking significant financial decisions.








