What is cash flow in a small business?

Cash flow is the actual movement of money through a business over time. Inflows include customer payments, loans, and other cash receipts. Outflows include payroll, supplier payments, rent, and debt service. A business can be profitable on paper while simultaneously running out of cash if its customers pay slowly and its own obligations come due sooner. That gap — between the timing of revenue recognition and the timing of cash receipt — is the core of most small-business cash-flow problems.

Accounts receivable is the single largest driver of cash-flow timing for service businesses. When customers pay late, outflows continue on their own schedule while inflows stall. Tightening DSO by even a week or two — through faster invoicing, clearer payment terms, and consistent early follow-up — releases working capital that the business was already owed but had not yet received.

Cash-flow problems and profitability problems look similar from the outside: both appear as an inability to pay bills. But they have different solutions. A cash-flow problem often clears when collections tighten. A profitability problem requires a different diagnosis entirely.