Three letters, from the friendliest to the firmest
The first reminder recalls the invoice, its number, its amount and its due date, without blame. It may be enough when the payment is late because of an oversight or a short-term difficulty. A call or an email will do.
The second reminder notes that the first one had no effect, sets a deadline of 8 or 15 days to pay and announces the formal notice. It is optional: Entreprendre Service Public, the French government’s site for businesses, advises against sending reminder after reminder.
The formal notice (mise en demeure) demands that the client pay within a set time, and says what will follow: an application to the court. Send it by registered letter with acknowledgment of receipt (lettre recommandée avec avis de réception). It will then be one of the documents of an application for an order for payment, along with the invoice.
None of these steps is required. If the client disputes the work or the amount, settle that disagreement first: a reminder won’t change anything.
In French or in English?
A French client expects a letter in French: the tool writes it in French by default. Pick English for a client who reads English, or to read what the French letter says before you send it. In both languages, the letter cites French law: the French Commercial Code (Code de commerce) for penalties between businesses, the French Civil Code (Code civil) for the formal notice.
What the letter must contain
- The invoice number and date, the amount still owed including VAT, and the due date.
- The sum claimed, with the penalties and the indemnity if you ask for them.
- The time given to pay, and how to pay: your IBAN, for example.
- For a formal notice, clear terms: “je vous mets en demeure de régler…” (“I hereby give you formal notice to pay…”).
- A copy of the invoice, attached.
Late payment penalties and the €40 indemnity
Between businesses, late payment penalties run from the day after the payment date written on the invoice, with no reminder or formal notice (French Commercial Code, article L441-10). If your terms and conditions set no rate, it is the ECB rate plus 10 points: 12.40% in the second half of 2026. A fixed indemnity of €40 for recovery costs comes on top, once per invoice, even after a partial payment, and without VAT.
The letter counts the penalties up to its own date, like our late payment penalties calculator, which gives the day-by-day detail and the mention to put on your invoices.
With a consumer, there are no Commercial Code penalties and no €40 indemnity, unless the contract provides for them. The formal notice starts interest running at the French legal interest rate (French Civil Code, article 1231-6): 2.75% a year in the second half of 2026 when the creditor is a business.
If the client still doesn’t pay
After the formal notice, you can file an application for an order for payment (requête en injonction de payer), with no lawyer required. It goes to the commercial court (tribunal de commerce) when you and your client are both traders, with €33.47 in court registry fees, and to the judicial court (tribunal judiciaire) in the other cases, for example if your client is a consumer or works in a liberal profession. The debt must be certain, liquid and due, and not time-barred.
For a sum under €5,000, a judicial officer (commissaire de justice) can also run the simplified procedure for recovering small debts, if your client agrees.
Frequently asked questions
Can I send a reminder for an unpaid invoice by email?
Yes. No form is required for a reminder: a call, an email or a letter. For the formal notice (mise en demeure), Entreprendre Service Public cites a registered letter with acknowledgment of receipt, in clear and formal terms, or a demand served by a judicial officer (commissaire de justice). That is what proves the client received it, and on what date.
How many reminders before a formal notice?
None is required: a reminder isn’t a prerequisite for a formal notice or for going to court. Entreprendre Service Public advises against sending reminder after reminder: if one gets no result, move on to the formal notice.
How long should I wait between two reminders?
No rule sets it. Give the client time to pay or to reply, for example 8 to 15 days, then move on to the next step. Between businesses, the wait changes nothing for the penalties: they run from the day after the due date.
How long do I have to claim an unpaid invoice in France?
After a certain time, you can no longer go to court: the claim is time-barred (prescription). According to Entreprendre Service Public, the period is 5 years between traders, or between a trader and a non-trader, and 2 years for a business claiming from a consumer.
What if the client disputes the invoice?
When the invoice is unpaid because of a disagreement about the work or the amount, a reminder doesn’t help, according to Entreprendre Service Public: first find a solution with the client, before any amicable recovery.
Should the letter be in French or in English?
A French client expects French: the tool writes the letter in French unless you pick English. Both versions cite the same French law. You can read the English version first, then send the French one.
Sources, in French: Entreprendre Service Public, “Recouvrement amiable : relance et mise en demeure de payer”, “Délais de paiement entre professionnels et pénalités de retard”, “Recouvrement judiciaire : injonction de payer en France et en Europe” and “Recouvrement judiciaire : assignation en paiement”; Service Public, “Recouvrement de dettes en France : injonction de payer et procédure simplifiée” and “Qu’est-ce que l’intérêt légal ?”. Consulted on October 24, 2026.