Most founders worry about sales. What actually shuts the doors is an empty bank account. A cash flow forecast is your best guess at the money coming in and going out over a set period, usually the next 12 months.
It tells you whether you’ll have enough in the bank when the bills land. If you don’t know what a cash flow forecast is, then read this article till the end.
- It’s about timing, not profit. Cash is counted once it’s landed.
- Short forecasts cover 30 days, long ones five years, and they blur the further you go.
- Opening balance, money in, money out, closing balance. That’s it.
- UK lenders will want to see one.
- Redo it monthly. Weekly if things are tight.
What Is A Cash Flow Forecast?
Basically, it’s a list. Cash you expect in, cash you expect out, pinned to dates. Start with your bank balance, add the first, and subtract the second, and there’s your closing figure. BBC Bitesize sums it up well: like a weather forecast, it is a PREDICTION: it has not happened yet. Don’t muddle it with a cash flow statement, though. A statement is history; a forecast is the road ahead.
Select Your Timeframe
Taulia splits it three ways. A short-term cash forecast may cover the next 30 days and can be used to identify any funding needs or excess cash in the immediate term. Medium-term runs from a month to a year.
Long-term stretches are one to five years, sometimes further, depending on what you do. However, the longer the time horizon of a cash flow forecast, the less accurate it is expected to be. Next month you can call. Five years out is astrology.
Five Components
- Opening balance — cash in your accounts on day one.
- Money in — sales, loans, grants, investment, interest, and asset sales, especially where business sales contracts affect payment timing.
- Money out — stock, rent, electricity, wages, suppliers, marketing, tax, loan repayments.
- Net cash flow — in minus out.
- Closing balance — where you finish and next month’s opening balance.
A Quick Example
| Item | Amount |
| Opening balance | £3,000 |
| Sales | £15,000 |
| Total inflows | £15,000 |
| Marketing | £1,000 |
| Employee wages | £6,000 |
| Rent and bills | £4,000 |
| Total outflows | £11,000 |
| Net cash flow | £4,000 |
| Closing balance | £7,000 |
Source: Internal Financial Records / Sample Cash Flow Model
Come out negative, you’d know today to chase invoices, delay a purchase, or ring the bank.
Why UK Startups Shouldn’t Ignore This
People pay late. Xero Small Business Insights data from 440,000 UK small businesses shows invoices are paid an average of 8.2 days late, with firms waiting an average of 29 days to be paid. The same research puts UK small business sales growth at 2.9% year-on-year, the smallest rise in two years.
Tax arrives in lumps. VAT goes to HMRC quarterly. Corporation tax lands annually. Both can wipe you out. Lenders insist. The British Business Bank requires a 12-month forecast from startup loan applicants. Two moments catch startups out.
At start-up, founders also need to understand what makes a successful startup business before taking on major fixed costs like equipment, stock, rent, insurance, hiring, and training, which are paid before a penny comes back.
And during rapid growth, when bigger premises and orders swallow cash faster than customers pay. Fast-growing and seasonal firms need this most — an ice cream van earns little in February. Keep getting it wrong, and you risk insolvency.
Forecast Or Budget? You Want Both
A budget sets your yearly targets and keeps spending in check. A forecast asks a blunter question: will the money be there on the day? Money notes: it also shows whether to cut overheads, chase investors, hire, or move somewhere bigger. Profit isn’t cash, either. You can look profitable on paper and be skint, because a sale isn’t money until someone pays.
Two Ways To Do It
The direct method lists real transactions by date. It’s simple and precise, and you need no accounting qualification. The indirect method starts with your profit and loss, then adjusts for non-cash items like depreciation and working capital. Better for long-range planning and investor talks. The FRC has noted most companies now disclose liquidity information such as available cash and undrawn borrowing facilities, so bigger firms lean that way.
How To Build A Cash Flow Forecast
- Choose your period—four to six weeks when new, twelve months for a loan.
- List income by date. Use last year’s figures if you have them.
- List every outgoing. Rent, payroll, VAT, insurance, and your own salary. Founders forget their own wages constantly.
- Work out the running balance, month by month or week by week.
Split recurring costs like rent from ad-hoc ones like travel and raw materials. Keep tidy records, mind seasonality, and be conservative on sales—surplus cash beats missing rent. Smartsheet has free templates.
What Usually Goes Wrong
Forecasting eats time, especially on spreadsheets with manual data entry, which invites typos too. Colleagues don’t send numbers on time. Nobody has decent tools. If senior management visibly backs the process, people cooperate. Then the lazy stuff: forecasting from your best month ever, assuming everyone pays on time, and never opening the file again. The fix is a feedback loop.
Compare the forecast against what actually happened, spot where you were wrong, and adjust. Cash flow forecasting software uses live and historical payables and receivables data, machine learning, visualisation, and ERP links to do the heavy lifting. But a spreadsheet you actually update beats clever software you ignore.
ALSO READ: A Beginner’s Guide: How Do I Start a Business With No Money?
FAQs
Q1. How Far Ahead Should A Startup Forecast?
Thirteen weeks for day-to-day control, twelve months for funding applications. Brand new businesses often start with four to six weeks and stretch it as data builds.
Q2. Is A Cash Flow Projection The Same Thing?
Yes, same tool, different word. Both estimate money in and out over a set period, though “projection” hints at a longer view.
Q3. Can I Just Use A Spreadsheet?
Absolutely, fine for simple forecasts. Just watch your formulas and remember you’re updating by hand.
Q4. What Goes In A Cash Flow Forecast?
Expected income and its dates, expected costs and theirs, plus opening and closing balances. Don’t skip taxes or your own pay.
Q5. Why Do Profitable Startups Run Out Of Money?
Profit counts a sale when you invoice it, not when you’re paid. Sixty-day terms and monthly payroll don’t mix well.
Q6. How Often Should I Update It?
Monthly at minimum, weekly if cash is tight or trade is seasonal. Redo it after any big order, lost client, or surprise bill.
Sources & References
- Wikipedia. (2026). Cash Flow Forecasting. In Wikipedia.
- Taulia. (2026). What is cash flow forecasting? Taulia Glossary.
- Xero. (2026). Cash flow forecasting guide. Xero UK Business Insights.
- BBC. (2026). Cash flow forecasting explained. BBC Bitesize Articles.
- Money.co.uk. (2026). Cash flow forecast guide. Money.co.uk Business Guides.
Disclaimer: The information provided in this article is intended solely for educational and informational purposes and does not constitute formal financial, accounting, or business advice. This content is not created for promotional purposes or endorsement of any specific services or software tools. Readers should consult a qualified financial advisor or accounting professional to evaluate their specific financial circumstances.
