Every year, businesses with full order books and healthy margins close their doors, and the post-mortem contains the same sentence in different words: the profit was real, but the money was not there when the bills arrived. Profit and cash are different measurements of the same business, and the gap between them — timing — is where otherwise sound firms drown in water that is, on paper, a perfectly good river.
The distinction is not accounting pedantry. Profit records a sale when the work is done; cash records it when the client pays, weeks later. Profit counts stock on the shelf as an asset; the bank counts it as money already spent. A growing business widens every one of these gaps automatically, which is the central paradox this article exists to explain: growth consumes cash, and the faster the growth, the faster the consumption.
We will walk the gap with a small example, name the three levers that control it — how fast you bill, how fast you are paid, how fast you pay — and finish with the rolling forecast, thirteen weeks of humble spreadsheet that remains the single most reliable survival instrument a small business can keep.
The gap, in one small business's month
A workshop lands its best month ever: 30,000 of work completed and invoiced. Its profit calculation is jubilant — costs of 21,000 against 30,000 of revenue, a 9,000 margin. Now watch the cash. The 30,000 is on 30-day terms, so it lands next month. This month's bank account receives last month's 18,000 (a quieter month), while paying this month's wages, materials bought for the big month's work, rent and a tax instalment: outgoings of 24,000. The account falls by 6,000 in the business's best-ever month. Nothing was mismanaged except the assumption that profit and cash are the same substance.
Stretch the example across a growth quarter and the pattern compounds: each month's costs are set by this month's booming workload, each month's receipts are set by last month's smaller one, and the account drains steadily behind the best trading in the firm's history. This is overtrading — the technical name for growing yourself illiquid — and it kills in the specific way cash kills: not with a verdict on the business's worth, but with a Tuesday where payroll cannot be met.
Working capital: the three levers
The money trapped in the gap has a name — working capital — and its size is set by three timings. Money owed by customers (receivables): the days between invoicing and payment, entirely visible in your invoice register, and the most controllable of the three through terms, prompt invoicing and the escalation ladder. Money in stock: every unit on the shelf is cash in costume, and its cost is not just storage but the weeks it sits — buying patterns are a cash decision as much as a price one. Money owed to suppliers (payables): the days you take to pay, which is the mirror image of your customers' behaviour toward you — legitimate to schedule honestly within agreed terms, corrosive to stretch silently.
The levers compound. Shave five days off customer payment, hold five fewer days of stock, and pay suppliers five days later within their terms, and a business turning over a million has freed something in the region of forty thousand of cash — permanently — without selling anything extra or borrowing anything at all. Owners hunt for growth and grants while this figure sits uncollected inside their own timings. The cheapest finance available to most small businesses is their own working capital, released.
The thirteen-week forecast: seeing the wall before the wall
The instrument is disarmingly plain: a rolling list of the next thirteen weeks, with expected receipts and payments placed in the week they will actually move — receipts by invoice due dates (adjusted by each client's real payment habits, not their stated terms), payments by payroll dates, rent, tax instalments, supplier runs and loan payments. Each week ends with a balance. Thirteen weeks is long enough to cover a full cycle of terms and tax, short enough that the estimates mean something, and the rolling part is essential: each week, last week is replaced by actuals and a new week thirteen is added.
Its power is not accuracy; it is notice. A shortfall visible six weeks out is a problem with options — accelerate two invoices with a courtesy call, schedule a supplier payment for the Friday after a large receipt lands, arrange an overdraft while the bank still thinks you are prudent. The same shortfall discovered on the morning itself is a crisis with an audience. Businesses that keep the forecast rarely describe themselves as lucky with cash; they have simply arranged to be warned, and warning is what the gap between profit and cash demands of anyone who intends to cross it regularly.
Key takeaways
- Profit records value when work is done; cash records it when money moves. The gap between them is timing, and it is where sound businesses drown.
- Growth widens the gap automatically: costs follow this month's workload while receipts follow last month's smaller one. That is overtrading.
- Working capital is set by three timings — customer payment days, stock days, supplier payment days — and small improvements in each free real cash permanently.
- Keep a rolling thirteen-week cash forecast, receipts dated by clients' actual payment habits. Its value is notice: six weeks to solve a shortfall instead of six hours.
- Collected tax and other held money is not your cash. A forecast that treats it as available is writing fiction with real consequences.
Mistakes to avoid
- Reading a profitable month on the accounts and assuming the bank balance agrees.
- Funding growth spurts from the tax sweep or the reserve because “the invoices are coming” — they are, and so is the tax bill, on its own schedule.
- Judging customer payment terms by what the contract says rather than the register's evidence of when they actually pay.
- Letting the forecast lapse in busy times — precisely when growth is stretching the gap the fastest.
Questions readers ask
How can I be profitable and overdrawn at the same time?
Because your profit includes sales not yet paid for and excludes the cash already spent on stock and next month's work. The two statements — profit-and-loss and bank balance — describe different things; a healthy business watches both, weekly, and plans from the cash one.
Is taking longer to pay suppliers a legitimate lever?
Paying on the last day of agreed terms is legitimate scheduling; drifting beyond terms without agreement is borrowing from your suppliers without asking, and it returns as worse prices, lower priority and, eventually, supply on pro-forma only. Use the days you agreed, no more.
What belongs in the forecast besides invoices and bills?
Everything that moves money on a date: payroll and its taxes, VAT or sales-tax remittances, loan payments, rent, insurance premiums, your own drawings, and the irregulars — annual licences, the December quiet patch. The irregulars are exactly the items that ambush a forecast built only from invoices.
Put it into numbers
Before forecasting, find your true break-even and your monthly fixed pile — cash planning starts from knowing the smallest month the business must survive.
Open the Break-Even Calculator