Seven Cash-Flow Leaks That Rarely Show in the Profit and Loss — and the 30-Minute Review That Plugs Them

Growing businesses rarely fail for want of a profit. They fail for want of timing — an overdraft that arrives three weeks before the invoice that would have cleared it, a VAT bill landing in the same week as a payroll run.

The profit and loss account is a poor early-warning system for this kind of trouble. It records revenue when it is earned and costs when they are incurred, which is the correct treatment for tax and for reporting, but tells you very little about what is in the bank next Friday. That is why a business can post a respectable margin and still spend the final week of every quarter chasing its own cash.

The seven leaks below are the ones we see most often in owner-managed companies and unincorporated firms alike. None of them is dramatic. Collectively they can absorb a startling proportion of a growing business's working capital.

1. Late payment from customers

The most familiar and least addressed. Invoicing on the day of delivery rather than at month end can bring forward a fortnight of cash across the whole ledger. A polite reminder seven days before an invoice falls due, and a phone call seven days after, recovers more than most escalation letters. Statutory interest under the Late Payment of Commercial Debts (Interest) Act 1998 remains available where terms are silent or unfair, though the relationship usually matters more than the interest.

2. VAT timing

VAT collected on sales is not the business's money, yet it sits in the current account looking exactly like the business's money until the quarterly return falls due. On a £40,000 quarterly VAT bill, a business that spends the balance in month two is borrowing from HMRC at rates it would never accept from a lender. Setting aside the VAT element of each invoice as it is raised — a separate reserve account is the simplest method — removes the shock without affecting the reported profit by a penny.

3. Payroll creep

Salaries and wages grow in small, agreeable increments: a modest rise here, an extra pair of hands there, employer pension contributions, the higher employer National Insurance rate and lower secondary threshold that took effect in April 2025. Each decision is defensible on its own. Taken together over eighteen months, they can add several percentage points to the cost base before any corresponding rise in revenue. Review total employment cost as a single figure each month, not line by line.

4. Duplicated subscriptions

Software sprawl is now one of the quietest drains in the typical small business. A card payment for a design tool that nobody has opened since a project ended, an annual renewal for a second project management platform after a change of team, overlapping accounting and invoicing apps. Individually these are £15 to £60 a month. A mature business can easily be carrying twenty of them.

5. Stock and work-in-progress build-up

Buying ahead of demand feels prudent and looks like an asset on the balance sheet. It is also cash converted into shelving. Where stock is seasonal, compare inventory days with the same month last year rather than with last month; the seasonal pattern will otherwise flatter or disguise the trend. Work in progress deserves equal scrutiny in service firms — unbilled time is a loan to the client, made interest-free and often without documentation.

6. Director's loans and owner drawings

Money taken out of a company by a director is not automatically a salary or a dividend. Where it is neither, it becomes a loan, with a benefit-in-kind consequence and, where it remains outstanding nine months after the year end, a 33.75% charge payable by the company. On a growing business's cash position this can be a fifth of the amount withdrawn, arriving at the worst possible moment. Keep a running director's loan account and settle it before the year end rather than after.

7. Vague credit terms

Where terms are unspoken, they default to whatever the customer prefers. Written terms — deposit, staged payments, a clear due date, a stated consequence for late settlement — change behaviour before any chasing is required. Deposits on bespoke work in particular convert a financing requirement into a customer obligation.

The monthly half-hour

None of the above requires a finance department. It requires thirty minutes, on the same day each month, with the bank feed open. A workable structure:

Minutes 0 to 5 — cash position. The current balance, plus a simple thirteen-week forecast. Even a rough one, written by hand, beats none.

Minutes 5 to 10 — aged debtors. Who owes what, how far past due, and which invoices will slip past sixty days this month. Pick the two largest and note the action.

Minutes 10 to 15 — committed spending. Direct debits due in the next four weeks, including VAT and any PAYE. Compare the total with the forecast balance on the day each falls.

Minutes 15 to 20 — tax reserves. Confirm the VAT and corporation tax or income tax set-aside still matches the liability as you understand it. If it does not, that is the finding of the month.

Minutes 20 to 25 — cost creep. Scan new or changed recurring payments. Anything unfamiliar gets a single question: what does this do and who uses it?

Minutes 25 to 30 — one action. Write down a single task, with a name and a date. Chasing three invoices is worth more than a beautifully formatted dashboard.

Making it survive a difficult month

The months when the review is most valuable are precisely the months when it is easiest to skip. Two safeguards help. First, fix the date and treat it as a meeting with a client. Second, keep it to one page — a diary note, a spreadsheet tab, a screenshot of the forecast. A review that takes an hour will be abandoned by the third month.

Delegate the preparation by all means. The reading of it, though, should stay with the owner. Cash is the one number that cannot be outsourced along with the bookkeeping.