Profitable businesses fail regularly, and the mechanism is nearly always the same: the money owed to them arrives more slowly than the money they owe. Profit is an accounting result measured over a period. Cash is a balance that must be positive every single day. A business can satisfy the first condition and be destroyed by the second.
Why profit and cash diverge
Under accrual accounting, revenue is recorded when earned, not when collected. Issue an invoice on thirty-day terms and the sale appears in this month’s profit — while the cash appears next month, or later.
Meanwhile, several large cash outflows never appear as expenses at all. Inventory purchases convert cash into an asset. Equipment purchases are capitalised and expensed gradually as depreciation. Loan principal repayments reduce a liability; only the interest hits the income statement. Tax is paid on a schedule unrelated to when the profit was earned.
The consequence is direct: a growing business consumes cash. Growth means buying more inventory and funding more receivables before collecting on any of it. The faster it grows, the more cash it absorbs — which is why rapid growth is a common cause of insolvency rather than a protection against it.
The cash conversion cycle
The cash conversion cycle measures how many days cash is tied up between paying suppliers and collecting from customers. It has three components.
- Days sales outstanding (DSO) — average days from invoice to payment.
- Days inventory outstanding (DIO) — average days stock is held before sale.
- Days payable outstanding (DPO) — average days taken to pay suppliers.
The cycle is DSO plus DIO minus DPO. A result of sixty days means the business funds sixty days of operations from its own resources before customer cash arrives.
Every day removed from that cycle releases cash permanently. This is the highest-return improvement available to most small businesses, and it requires no additional sales.
Some businesses run a negative cycle — collecting before paying suppliers. Subscription services billed annually in advance and retailers with fast stock turnover and long supplier terms are the common examples. A negative cycle means growth generates cash rather than consuming it, which is a structural advantage worth designing toward deliberately.
The thirteen-week forecast
The single most useful cash management tool is a rolling thirteen-week forecast: a week-by-week projection of cash in, cash out, and closing balance, extended by one week every week.
Thirteen weeks is the conventional horizon because it is long enough to reveal a problem while there is still time to act, and short enough that estimates remain grounded in known commitments rather than speculation.
Build it on timing, not averages. Weekly granularity matters because monthly totals conceal the problem: a month in which payroll and a quarterly tax payment fall in the same week can average out comfortably while the business runs out of money on a Tuesday.
Include everything that moves cash: payroll and associated taxes, rent, loan repayments including principal, tax instalments, insurance renewals, subscriptions and any seasonal outlay. Forecast receipts by expected payment date, based on how each customer actually pays, not by invoice due date.
A spreadsheet is sufficient. Consistency matters far more than sophistication.
Getting paid faster
Receivables are usually the largest controllable component of the cycle.
- Invoice immediately. Delay between delivery and invoicing is pure self-inflicted DSO. Invoicing weekly rather than monthly can remove two weeks from the cycle at no cost.
- Make terms explicit before work begins. Payment terms, accepted methods and late-payment consequences belong in the engagement agreement, not discovered in dispute.
- Take deposits. For project work, staged payments — deposit, milestone, completion — transform the cash profile and reduce exposure to a single non-payer.
- Chase systematically. A defined sequence — reminder before due, contact on day one overdue, escalation at defined intervals — collects substantially more than sporadic chasing, mostly because it signals that the business tracks payment closely.
- Remove friction. Accept the payment methods customers prefer. Card fees are frequently cheaper than the financing cost of an extra three weeks of DSO.
- Check credit on large accounts. A significant new customer is an extension of unsecured credit and warrants the same scrutiny a lender would apply.
Managing outflows without damaging relationships
Extending payables improves the cycle, and is easily overdone.
Negotiate longer terms openly rather than simply paying late. Suppliers can often accommodate a request they have agreed to, and will not accommodate unilateral behaviour. Paying late without discussion damages supplier relationships, forfeits early-payment discounts and can result in supply being withdrawn at the worst moment.
Assess early-payment discounts arithmetically. A discount for paying twenty days early can represent a very high annualised return on the cash used — frequently better than any alternative use of it. Conversely, when cash is scarce, forgoing the discount is a form of borrowing whose cost should be compared against the credit line.
Match asset financing to asset life. Funding long-lived equipment from working capital drains the buffer that covers operations.
The buffer
A cash reserve is not idle capital. It is what allows a business to survive a late-paying major customer, a delayed contract or an unexpected repair without distress.
How much depends on volatility: businesses with concentrated customers, seasonal revenue or long cycles need more. The practical way to size it is to model the specific failure that would hurt most — the largest customer paying sixty days late — and hold enough to absorb it.
Arrange credit facilities before they are needed. Lenders assess businesses most favourably when they are not desperate, and a line arranged in good conditions is available in bad ones. An unused facility costs little; an unavailable one costs the business.
Customer concentration
A customer representing a large share of revenue is a cash flow risk regardless of how reliable they seem. Their payment behaviour, their internal reorganisations and their own solvency all become the supplier’s problem.
Concentration also removes negotiating power over terms, which tends to lengthen DSO precisely where the exposure is largest.
Early warning signs
- DSO rising over consecutive months.
- Increasing reliance on the credit line to cover payroll.
- Inventory growing faster than sales.
- Paying suppliers later without having negotiated it.
- Tax liabilities accumulating unpaid.
- Growth in revenue with no corresponding growth in the bank balance.
Each of these is visible months before it becomes critical, and each is far cheaper to address early than late.
Related reading
For the same analysis applied to published company accounts, see reading a cash flow statement. For how business structure affects tax timing, see choosing a business structure.
This article is general information and journalism, not financial, accounting or legal advice. Consult a qualified professional about your circumstances. See our Editorial Policy.