Profit measures what remains from revenue after costs. Cash flow tracks money moving in and out. They answer different questions, so a profitable job can still leave you waiting for the cash needed to pay your next supplier. Looking at both makes the problem easier to identify.
The useful bits
- A healthy margin does not tell you when a customer will pay.
- A bank deposit is not always sales income.
- Review job costs and payment timing separately.
Ask two separate questions
For the job itself, ask: does the price cover the costs of delivering it and contribute towards running the business? For the bank balance, ask: will the money arrive before the payments connected with that work fall due?
The British Business Bank explains that a business can be profitable while still having poor cash flow. The practical response depends on which problem you have. A price that does not cover costs needs a different conversation from a well-priced job whose invoice has not been paid.
Follow one job from booking to payment
Imagine a £1,000 job with £600 of direct costs. That leaves £400 before overheads, tax and any other costs. Calling the full £400 take-home profit would miss those further commitments.
Now add the timing. You begin with £800 in the bank, pay the £600 costs this week and receive the customer’s £1,000 next month. Your balance falls to £200 in the meantime. The planned margin has not put money in the account yet.
Illustrative figures, not a tax calculation
Job value £1,000 − direct costs £600 = £400 contribution before other costs. Immediate bank movement: £800 − £600 = £200. Later customer receipt: £200 + £1,000 = £1,200, assuming no other movements. This example is about timing, not the tax treatment of income.
Do not read the bank balance as a profit report
A loan or money you introduce can increase cash without being a new customer sale. Paying back borrowing or taking money out personally also needs to be distinguished from the direct cost of a job. Label these movements clearly so they do not disguise how the work itself is performing.
Likewise, money already in the bank may be needed for supplier invoices, refunds or upcoming tax payments. Keep those commitments visible in your forecast instead of treating the account balance as an amount available to spend.
Keep management decisions separate from tax reporting
The way income and costs appear in tax records depends on the accounting method and rules that apply to you. HMRC distinguishes cash basis from traditional accounting; do not use this simplified job example to decide what belongs on a tax return.
Ask your accountant how to read your reports, particularly if invoice totals, payments and reported profit seem to disagree. Bring the invoices and payment dates so they can explain the actual difference rather than working from a bank-balance screenshot.
Use a small weekly review
Review the latest completed job and the next four weeks of cash together. If costs repeatedly overrun, improve your estimates and approval process. If customers pay after suppliers need paying, work on the agreed payment schedule and follow-up process.
Write down which issue you are addressing. “Need more sales” is too broad when the immediate problem is an unpaid invoice, and taking more work can add costs before it adds cash.
Sources and further reading
Sources checked 28 September 2026. Follow the official guidance for the current rules and how they apply to your business.
