An unpaid invoice rarely means a dishonest client. More often, it is sitting in an accountant's inbox, missing a purchase order number, or the client is short on cash. The trouble is that by waiting so as not to upset anyone, you end up chasing it three months later, annoyed, with an email that damages the relationship.
This article gives you a method and ready-to-copy wording, from a polite reminder to a formal notice. The legal rules quoted here are French rules for invoices between businesses. If you or your client are based elsewhere, the structure of the reminders still works, but check your own country's rules for penalties and fees. For quotes that got no reply, see my quote follow-up email templates.
Please note. I'm not a lawyer. The rules below come from the French government's service-public.fr and from Legifrance (the official French law database), checked on October 17, 2026, with links at the end. For a real dispute or a large amount, have your approach checked by your accountant or a lawyer.
What does French law say about late payment between businesses?
Three rules from the French Commercial Code (article L441-10) frame everything that follows. They apply between businesses, not to consumers.
| Rule | What it says | Source |
|---|---|---|
| Payment term | 30 days after delivery or service by default. If agreed: 60 days maximum from the invoice date, or 45 days end of month if the contract expressly says so. | Commercial Code, art. L441-10, I |
| Late payment penalties | Due from the day after the due date, with no reminder required. Minimum rate: three times the French legal interest rate. If no rate is set, the ECB rate plus 10 percentage points. | Commercial Code, art. L441-10, II |
| Flat recovery fee | 40 euros, owed automatically by the business that pays late. If your actual recovery costs are higher, you can claim the difference with proof. | Art. L441-10, II and art. D441-5 |
Service-public.fr adds that the 40 euro fee is due once per invoice, not per day of delay, even if the invoice is partly paid, and that it is not subject to VAT. The same page gives the default rate (ECB plus 10 points) for 2026 as 12.15% for the first half and 12.40% for the second half.
Two practical consequences. First, these terms must appear in your terms of sale and on your invoices: check your templates before you chase anyone. Second, you don't need to wait for a formal notice to claim them: you can mention them in the first reminder, in a neutral tone.
What schedule should you follow for overdue invoice reminders?
The law sets no schedule for friendly reminders. This one is a suggestion for an everyday invoice; tighten it if the amount matters to your cash flow.
| When | Action | Tone | Template |
|---|---|---|---|
| 3 to 5 days before the due date | Courtesy reminder (optional) | Helpful | No. 1 |
| Day 2 after the due date | First reminder by email | Polite, assume an oversight | No. 2 |
| Day 12 | Second reminder by email, then a call | Firm, factual | No. 3 |
| Day 25 | Third reminder, announcing the formal notice | Formal | No. 4 |
| Around day 35 | Formal notice by registered mail with acknowledgment of receipt | Legal | No. 5 |
Which email templates should you use, from first reminder to formal notice?
Replace the parts in brackets. Always keep the invoice number, the due date and the amount in the text: your client's accounts payable team needs them to find the document.
1. The courtesy reminder before the due date
SubjectInvoice [INV-2026-041]: due on [date]
Day -3
Hi [Name], to make things easier on your side, I'm attaching invoice [INV-2026-041] for [1,200] for [the service], due on [date]. If a purchase order number or any detail is missing, let me know before the due date.
INV-2026-041.pdf
2. The first reminder
SubjectReminder: invoice [INV-2026-041] due on [date]
Day 2
Hi [Name], unless I'm mistaken, I haven't received payment for invoice [INV-2026-041] for [1,200], which was due on [date]. It's probably an oversight: could you check on your side? If the payment is already on its way, please ignore this message.
INV-2026-041.pdf
3. The second reminder
SubjectSecond reminder: invoice [INV-2026-041] unpaid
Day 12
Hi [Name], invoice [INV-2026-041] for [1,200], due on [date], is still unpaid despite my reminder of [date]. Could you tell me when the payment will be made? As set out in my terms of sale, late payment penalties at [X%] and a flat recovery fee of 40 euros apply to late payments. If there is an issue with the invoice, call me at [number]: I'd rather sort it out quickly.
INV-2026-041.pdf
4. The third reminder, before the formal notice
SubjectFinal reminder before formal notice: invoice [INV-2026-041]
Day 25
Hi [Name], despite my reminders of [date] and [date], invoice [INV-2026-041] for [1,200], due on [date], is still unpaid. If I don't receive payment by [date, about 8 days out], I will send you a formal notice by registered mail. As of today, late payment penalties of [calculated amount] and the 40 euro flat fee are added to the principal. I'm available at [number] if you'd like to agree on a payment plan.
INV-2026-041.pdf
5. The formal notice to pay (mise en demeure)
In France, this goes by registered letter with acknowledgment of receipt (paper or electronic): it gives you dated proof, which matters if you later go to court. You can send a copy by email.
SubjectFormal notice to pay: invoice [INV-2026-041]
Registered
[Your company, address, registration number] to [Client company, address]. [Place, date]. Dear Sir or Madam, I hereby give you formal notice to pay, within [8] days of receiving this letter, the sum of [1,200] for invoice [INV-2026-041] dated [date], due on [date], which remains unpaid despite my reminders of [dates]. Added to this sum are the late payment penalties set in my terms of sale at [X%], amounting to [amount] as of [date], and the 40 euro flat recovery fee provided for by articles L441-10 and D441-5 of the French Commercial Code. Failing payment within this period, I will start court recovery proceedings, including an application for an order for payment. Yours faithfully, [Signature]
INV-2026-041.pdf
How do you calculate late payment penalties?
The usual formula: amount due × annual rate × days late ÷ 365. Example with the default rate for the second half of 2026 given by service-public.fr (12.40%): for 1,200 euros paid 30 days late, 1,200 × 12.40% × 30 ÷ 365 = 12.23 euros in penalties, plus the 40 euro flat fee.
Use the rate in your terms of sale, as long as it meets the legal minimum. If you're unsure about the calculation base or the rate, your accountant will settle it in five minutes.
What if the formal notice doesn't work?
In France, the simplest route for a small contractual debt is the order for payment (injonction de payer), a written procedure described on service-public.fr (page checked on September 1, 2026):
- the application goes to the commercial court if your client is a trader, otherwise to the judicial court, in the area of the debtor's address or registered office;
- court registry fees are 33.47 euros at the commercial court and nothing at the judicial court; you pay the bailiff (commissaire de justice) who serves the order;
- since September 1, 2026, the order must be served within 3 months or it lapses;
- your client then has one month to object.
Attach the invoice, the contract or signed quote, your reminders and the formal notice with its acknowledgment of receipt. That is why it pays to keep a record of every reminder.
Can overdue invoice reminders be automated?
Reminders 1 to 3 automate well: they depend on a due date and a payment status. Your invoicing software may already do it; if not, a tool like n8n or Make reads the list of invoices, sends the right reminder from your address and stops as soon as the payment is recorded. It works the same way as automated quote follow-up, and I walk through a full workflow in automating unpaid invoice reminders with n8n.
Reminder 4 can be drafted automatically, but I recommend reading it before it goes out. The formal notice is a decision you make by hand. If you'd like to hand off the setup, it's a typical payment reminder automation project: usually one to two weeks, testing included.
Which cases should you handle by hand?
- The client disputes the invoice. An automated reminder on a disputed invoice makes things worse. Pause the reminders and settle the disagreement.
- The client is in insolvency proceedings. Article L441-10 then rules out claiming the penalties and the flat fee, and recovery goes through a formal claim in the proceedings: talk to your accountant.
- The client is a consumer. The penalties and the 40 euro fee described here apply to businesses that pay late. Other rules apply to consumers.
- A payment plan has been agreed. Reminders should follow the new schedule, not the old due date.
- Large strategic clients. A call to the right person (often accounts payable) gets results faster than a third email.
Sources checked on October 17, 2026 (in French)
- Service-public.fr (Entreprendre), payment terms between businesses and late payment penalties, page checked by its editors on August 7, 2026
- Service-public.fr (Entreprendre), court recovery: order for payment in France and Europe, page checked by its editors on September 1, 2026
- Legifrance, French Commercial Code, article L441-10: Legifrance shows this version applies until January 1, 2027, so check the text again after that date
- Legifrance, French Commercial Code, article D441-5 (40 euro fee)
Frequently asked questions
How many reminders should you send before a formal notice?
French law sets no number. In practice, three reminders (polite, firm, then one announcing next steps) followed by a formal notice by registered mail give the client every chance to pay and give you a solid file.
What should a third overdue invoice reminder include?
The invoice number and amount, the due date, the dates of earlier reminders, the penalties and the 40 euro flat fee (under French law), and a deadline after which you will send a formal notice. Offer a payment plan too if the relationship is worth keeping.
Can you claim the 40 euro fee from the first day of delay?
Yes, between businesses under French law. The Commercial Code makes the late-paying business liable for it automatically. It is due once per invoice, not per day of delay.
Can a formal notice be sent by email?
An email leaves a record, but a registered letter with acknowledgment of receipt, paper or electronic, proves the date of receipt better. That is what I recommend, with a copy by email.
How much time should a formal notice give the client?
A clear and reasonable deadline that you set yourself, for example eight days from receipt. Give an exact date: it is the starting point for what comes next.