Cash flow problems feel like weather: something that happens to you. They are not. Almost every one traces to a handful of mechanical causes, each with a known fix. Here they are, in the order they usually hurt.
The context that makes this urgent: the JPMorgan Chase Institute, analyzing real account flows across hundreds of thousands of small businesses, found the median small business holds just 27 days of cash buffer. Under a month. Whatever cause hits you, that is how long the median business has to absorb it — which is why the same slow month is an inconvenience for one company and an existential event for its neighbor.
1. Money arrives slower than it leaves
The most common cause, and the least discussed, because it is not a sales problem. You deliver in March, invoice in April (late), on net 30 terms (long), and the customer pays in June (later). Meanwhile payroll left in March, April and May. The work was profitable; the timing nearly killed you.
The fix is mechanical, not motivational. Invoice the day you deliver — every day between delivery and invoice is a free loan you extended by being slow. Shorten default terms: 14 days is normal for services, and the customer who walks over 14-versus-30 was going to pay late anyway. Take deposits on project work. Put late-payment interest in the contract — in the EU it is a statutory right, and a late payment interest calculator turns it from a vague threat into a number on the reminder email. The full system is in getting paid on time.
2. Seasonality with no reserve
Seasonal revenue is not a problem; seasonal revenue treated as a surprise is. A business that earns 70% of its revenue in six months and spends evenly across twelve has a completely predictable shortfall — and most walk into it with the median 27-day buffer anyway.
The fix is a reserve sized to the trough, not to a generic rule. Add up the net cash the quiet months consume, and that is the minimum the strong months must bank. The cash reserve calculator sizes the target to how your revenue actually arrives, and the discipline for filling it — from profit, on a schedule, before discretionary spending — is the same reserve-first sequencing as paying yourself.
3. Cash locked up in inventory
For product businesses: every unit on the shelf is cash converted into a bet. Order too much and the money is not gone, exactly — it is imprisoned, and it does not pay rent while it waits. Overstocking usually comes from ordering on optimism (next quarter's hoped-for sales) or on supplier discounts that are only cheap per unit.
The fix is ordering tied to the sales rate. Reorder when stock hits the level that covers your actual lead time at your actual sales pace, not when the quarterly habit says so. A bulk discount is only a discount if the cash it locks up was not needed for anything else — price the discount against your buffer, not against the unit cost.
4. Prices too low to fund the gap
Underpricing shows up as a cash problem before it shows up as a profit problem. Thin margins mean every job barely covers its own costs, so there is never surplus to fund the float between paying expenses and collecting revenue — you feel busy and broke at the same time, which is the signature symptom.
The fix is the one founders resist longest: raise prices. Price is the only lever that adds cash without adding work or cost. Most owners overestimate how many customers a sensible increase loses, and the arithmetic of raising prices without losing customers usually shows you can lose more customers than you think and still come out ahead on cash.
5. Growth outpacing collections
The cruelest cause, because it punishes success. Every new customer costs cash now — labor, materials, onboarding — and pays later. Grow fast enough on slow terms and the gap between spending and collecting widens every month. This is how businesses grow themselves to death: record revenue, empty account.
The fix is modeling the cash cost of a sale before taking it. If a new contract means €10,000 out this month against €15,000 in ninety days, growth speed is a working-capital decision, not just an ambition. A cash flow tracker makes the gap visible line by line, and when will you run out of cash turns it into the date that actually disciplines the decision.
The pattern behind all five
Notice what the causes share: none of them is about earning too little. They are all timing — money out before money in, at different scales. That is why the universal second fix, whatever the first one is, is the buffer. A business with three months of expenses in reserve experiences these same five causes as annoyances. The median business, at 27 days, experiences them as emergencies.
So the order of operations when cash feels tight: know your number first — track the ledger weekly, not monthly, when it is bad, whether in a spreadsheet or in startup finance software that keeps it current for you. Fix the cause that is actually yours, using the list above. And build the reserve with the surplus the fix creates, so the next cause finds a shock absorber instead of a crisis.