A business can be profitable on paper and still run out of money. It happens more often than owners expect, and it rarely comes from one big mistake. Usually it’s a mix of small, predictable gaps between what the income statement says and what’s really in the bank. Here are five of the most common causes.

1. Growth outpaces cash conversion

Winning new business feels like success, but growth often consumes cash before it produces it. You may need to buy inventory, pay staff, or cover supplies weeks or months before the resulting sale is collected. The faster you grow, the more cash gets tied up in that gap, even if profit on paper looks strong.

2. Customers pay slower than suppliers get paid

Profit is recorded the moment a sale happens. Cash arrives only when the invoice is actually paid. If customers take 60 or 90 days to pay while suppliers expect payment in 30, that mismatch drains cash steadily, invoice by invoice, even on a fully profitable book of business.

3. Debt repayments don’t show up on the income statement

Loan interest reduces profit, but principal repayments don’t. They only reduce cash. A business can report a healthy profit and still see its bank balance shrink every month simply because loan or lease payments are quietly leaving the account without ever touching the P&L.

4. Cash gets locked into equipment or inventory

Buying equipment, vehicles, or building up inventory to meet demand converts cash into assets that don’t move. That spending is often only partially reflected in profit for the period, through depreciation, so the P&L understates just how much real cash walked out the door.

5. Nobody is watching cash flow specifically 

Most owners track profit monthly through the P&L, but not cash on a shorter cycle. Without a rolling view of what’s coming in and going out over the next several weeks, cash shortfalls appear suddenly, even though the underlying causes were building for weeks. 

The fix isn’t complicated: track cash separately from profit, and look forward, not just back. A simple rolling cash flow forecast, reviewed weekly, gives you the early warning that a monthly P&L never will.