Unpaid invoices: the automatic follow-up sequence that gets the money in

A tradesperson showed me his spreadsheet of unpaid invoices during a Scan, one morning in June. Three columns, twenty eight rows, a total at the bottom he didn't comment on. Invoices overdue for six weeks, for three months, and one since last autumn. His order book was full; his bank account wasn't. These aren't the same problem, and the second kills far faster than the first.

When I asked him why he hadn't chased them, he gave me the answer almost every business owner I see gives me: "I don't have the time, and anyway he's a good client, I don't want to put him off." Both halves of that sentence are wrong. Here's why, and here's the sequence I install instead.

Why are your unpaid invoices never chased?

Because chasing has no trigger. A quote is a client calling you; an invoice is you having to remember, some evening, on top of everything else, to make a move nobody enjoys making. It isn't negligence, it's mechanical: nothing in your day reminds you that an invoice has been overdue for eleven days. The spreadsheet doesn't speak.

"He's a good client, I don't want to put him off."

That fear is real, and it costs dear: the Banque de France measures that late payments increase the risk of failure for the business on the receiving end by 25%. The Senate goes so far as to propose banning the waiving of late payment penalties, precisely because small suppliers waive them out of fear of losing an important client. The reflex not to put the client off, lawmakers have identified as a factor in business failure.

What does the law say when your invoice is paid late?

It's markedly more on your side than you think. Between businesses, late payment triggers penalties and a €40 compensation, automatically, with no need for you to claim them or even send a reminder. Three things to know:

• The deadline. Unless you agree otherwise, payment is due 30 days after the goods are received or the service performed. If you agree something else, the cap is 60 days after the invoice is issued, or 45 days end of month provided it's written into the contract (article L441-10 of the Commercial Code).
• The penalties. The text is clear: "late payment penalties are due without any reminder being necessary." They start running the day after the due date. In the absence of a rate set out in your terms of sale, it's the European Central Bank's refinancing rate plus 10 points, and your terms can't go below three times the statutory interest rate.
• The €40. Any business paying late owes a flat-rate compensation for recovery costs set at €40 (article D441-5). Per invoice, not per client: five overdue invoices means five times €40.

The trap is the invoice itself. Article L441-9 requires you to state the penalty rate and the amount of the recovery compensation on it. Many small businesses I see mention them nowhere, neither on their invoices nor in their terms and conditions. They deprive themselves of a free argument, and expose themselves to an administrative fine.

Sources: Commercial Code, article L441-10 (deadlines, penalties due with no reminder, rate) · article D441-5 (flat-rate €40 compensation) · article L441-9 (mandatory mentions on the invoice and penalties) · French Senate, Law Committee, "Tackling late payments and business failures," February 2026 (€15.3bn cash-flow shortfall for French SMEs, 2024 figure from the late payment observatory; 25% increased risk of failure according to the Banque de France).

What does a follow-up sequence that gets you paid look like?

Three messages, on three fixed dates, with three tones that escalate. That's it, and that's what works: most invoices get paid at the first or second message, because the real cause of the delay is almost never bad faith. It's forgetfulness, on the other side too.

The formal notice isn't an aggressive move, it's a technical one. It starts the statutory interest running (article 1231-6 of the Civil Code) and it's the document you'll be asked for if you go further, with a payment order before the Commercial Court. Without it, your case doesn't exist. With it, most clients pay within 8 days, because they understand what comes next is already written.

Note the progression: each message is shorter than the last. The first explains, the last states. It's the opposite of the email written by feel, which gets longer and more apologetic as the anger rises.

What changes, once it's automated?

It changes who decides. Today it's your mood that evening; once the sequence is automated, it's the due date, and it never loses its nerve in front of a good client. The rest follows:

• The three messages go out without you, on the right dates, with the right amounts pulled from the invoice.
• The sequence stops the second the money arrives. That's the most important point of the system, and I come back to it just below.
• The tone stays yours. The messages are written with you, in your own wording. A client receiving a follow-up shouldn't sense software behind it.
• You keep control: for most of my clients, the first message goes out on its own, the next two go through a one-click approval. You decide whether to step it up.
• You see where things stand: one line per invoice, the stage it's at, what's come in this week.

This is one of the pieces we installed for the plumber whose day I told you about here: unpaid-invoice follow-ups sent on a schedule, with a message written in his own tone. What he gained wasn't just money coming in faster. It was no longer thinking about it in the evening.

What can go wrong?

A follow-up sent to someone who's already paid. That's the one real risk, and it happened in the very first week with a client: a transfer received the evening before, not yet reconciled in the accounts, and a firm follow-up went out the next morning to a client who was perfectly up to date. Three lines of email, and a relationship damaged for nothing.

The lesson fits in one sentence: the source of truth is never the invoice, it's the payment received. Since then, no sequence I install goes out without first checking the money received, with a two-day safety margin to let transfers arrive, and a list of exceptions the owner keeps themselves: clients in dispute, those with a payment plan agreed, the one they've promised to wait for until the job's finished. An automation that doesn't know your trade's exceptions isn't an automation, it's a mail merge.

And there's what it will never do in your place. Decide whether to go to court over €1,400. Sense that a normally punctual client pushing their payment back three weeks might be going under, and that it's better to call them than to chase them. That's you, and it has to stay you. The machine gives you back the time to do it.

Where to start, alone, this week?

The first three steps need nobody else, and they're already worth money. Allow an hour.

1. Make the list. Every unpaid invoice you have, with the due date and the number of days overdue. Not the amount: the number of days. That's the one that hurts to look at.
2. Fix your invoice template. Penalty rate and €40 compensation in the footer, once and for all. Same in your terms and conditions.
3. Send the three messages by hand on your three oldest invoices, with the tones from the table above. Put the dates for the next ones in your diary, with an alarm.

Do it for a month. Either you keep to the dates, and you don't need me: the money will come in faster from the second week. Or you don't keep to them, like almost every business owner I meet, and you'll know exactly what to automate, and why. Either way, you'll have gained.

To see what these systems look like once installed, my page on automating follow-ups and unpaid invoices details what gets connected most often for tradespeople and small businesses, and what it costs.

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