Anticipating and reducing unpaid invoices in construction

In construction, you front almost everything: materials bought, wages paid, subcontractors settled, well before the invoice is cashed. A single large unpaid invoice can therefore tip over a business that is profitable on paper. It is not the lack of projects that causes the most failures, it is the lack of cash.

The sector stacks up risk factors: high amounts, long payment terms, a subcontracting chain where one party's delay cascades onto the next, and contracts where the final balance only arrives after a handover that is sometimes disputed. When a client is late, it is not just a pending line: it is an overdraft, interest charges, and time spent chasing money instead of building.

The good news: an unpaid invoice is almost never a total surprise. It announces itself through delays that stretch out, partial payments, late disputes. Learning to read these signals, and acting before the debt becomes unrecoverable, changes everything.

The best predictor of a client's future behaviour is their past behaviour. For a recurring client, you already hold the raw material: their payment history. Three indicators capture the essentials. First, the late ratio — the share of their invoices settled late. Then the average payment delay, in days beyond the due date. And the average amount involved in those delays, because a €200 delay does not weigh like a €20,000 one.

From this objective data, you can build a payment risk score. It is a deterministic calculation, not a crystal ball: you weight the late ratio, the average delay and the size of the overdue amounts to produce a figure. The higher the figure, the more the client has, in the past, paid late or incompletely. There is no artificial intelligence in it — just arithmetic applied to your own invoices.

This score is not a verdict, it is a signal. A poorly rated client is not one to turn away: it is one to secure more tightly — a higher down payment, closer milestones, a reminder from the first day of delay. Constrigo offers this payment risk score, calculated on invoice history, to make objective a decision that was until now made on instinct.

The best reminder is the one you never have to send. It all plays out before the job, in the quote and the payment terms. Ask for a down payment on order — often 30% — and plan staged payments tied to progress rather than a single balance at the end. The closer the milestones, the smaller your exposure if the client stops paying.

Get the contractual frame right. Clear terms of sale, a quote signed before work starts, written payment terms, and a mention of the late-payment penalties and the fixed recovery indemnity legally due: these are not formalities, they are your levers the day things go wrong. On large works contracts, the client's retention guarantee has its counterpart on your side: a bond, a payment guarantee.

Finally, match the level of security to the real risk. A new client, or one with a high risk score, justifies a larger down payment and tighter milestones; a loyal client who pays like clockwork can be given more flexible terms. Securing is not distrusting everyone: it is putting the effort where the risk is.

When a delay happens, speed matters more than firmness. A debt is recovered all the better for being handled early. Put a simple routine in place: a courteous reminder as soon as the due date passes, a firmer chase one to two weeks later, then a formal notice by registered letter. Keeping a written trace of each step is not red tape: it is what makes any procedure credible.

The formal notice is a turning point. It restates the sum due, sets a final deadline and signals what comes next. It starts the late-payment interest running and often conditions any court action. If it goes unheeded, several routes exist depending on the amount and the debtor's profile: the payment order procedure, fast and cheap for uncontested debts, or calling on a judicial officer.

Two principles to close. First, never let a debt age: past a certain point, recovery becomes illusory and the limitation period looms. Second, treat chasing as a process, not a fit of anger. Regular tracking of due dates and an up-to-date payment history — the very data that feeds the risk score — let you chase the right client, at the right time, with the right tone. It is less exhausting, and far more effective.