No customer wakes up one morning and decides to stop paying. It happens slowly, in a pattern most jobbers have seen before and still manage to miss, because the signs are quiet and the account is usually one you like. By the time the balance is big enough to hurt, the warning has been there for months. It is far easier to act on early, back when acting still feels like an overreaction. Here is roughly the order it shows up.
It starts with the calendar
The first sign is timing, not amount. The check still comes and still clears, it just comes later. Net 10 becomes net 18. The month after, net 25. Nothing looks wrong, the balance gets paid, so it is easy to wave off. But a healthy customer pays on a rhythm, and the rhythm is the first thing to go when money gets tight. You only catch it if you are watching the days to pay account by account instead of glancing at the total on the aging report.
Then the tone changes
Healthy accounts are quiet. They take the fuel, they pay the bill, you talk about the weather. An account in trouble gets noisy in a particular way. It starts questioning invoices it never questioned. It asks for copies, disputes a freight line, wants a few days to look into a bill that is plainly right. Some of that may be genuine. A sudden appetite for friction, though, is often a customer buying time and hunting for a reason to hold a check. The disputes are small. The pattern is the message.
You learn where you rank
A business short on cash does not stop paying everyone. It pays the vendors it cannot run without and stretches the rest, and it pays the ones who push hardest before the ones who are patient. Watch for the tell. They keep the fuel current because the trucks have to roll, but the older balance just sits. Or a flat, round payment lands that matches no invoice, enough to keep you from calling. That partial check is not good news. It is triage, and you are being managed.
There is a harder version of this one. The account asks for more right as it slows down. A bigger line, an extra load, terms stretched to net 30 for a couple of months. Sometimes that is a company stepping up. Sometimes it is a company filling a hole with your fuel. The slowing payments tell you which version you are looking at.
The quiet at the end
The last sign is silence. Calls go to voicemail. The owner is out, will call back, does not. The yard still takes the delivery, but the office has gone dark. By the time an account stops talking, the decision has usually already been made, and all that is left to settle is how much you are owed when the music stops.
What a careful jobber does
None of this asks you to suspect every customer. It asks you to watch the few numbers that move first, per account, not in a lump. Days to pay, by customer. The aging that creeps. A balance that grows while the payments shrink. When the pattern shows, the move is not dramatic. Tighten the terms. Ask for the older balance before the next load goes out. Put a sliding account on prepay or COD for a while. It feels unkind in the moment, and the customers who are fine will grumble and stay. The ones who are not fine are the whole reason the policy exists. Guarding your receivable is how you keep serving everyone else on the route.
Most bad debt is not a surprise. It is a run of small signs that were easier to read than to act on. The jobbers who rarely get burned are not luckier than the rest. They are the ones looking at the accounts inside the number instead of the number itself.