The formal notice: definition, legal effects and how to write one

An unpaid invoice, a service never delivered, a neighbour who will not stop a disturbance, a repair that drags on: before going further, one step is often called for — the formal notice (mise en demeure). It is a simple act, but with real legal effects. Here, in a documentary way, is what it is, what it is for and how to write it.

What is a formal notice?

The formal notice is a formal demand by which you require someone to perform their obligation: to pay, deliver, repair, stop a disturbance. It is not a mere friendly reminder; the law recognises a value of its own to it. Article 1344 of the Civil Code states:

"The debtor is given formal notice to pay either by a summons or a deed constituting a sufficient demand, or, if the contract so provides, by the mere fact that the obligation has fallen due."

What legal effects does it produce?

The formal notice triggers several effects that a mere reminder does not produce:

• It sets default interest running. On a money debt, it sets default interest at the statutory rate running, without your having to prove any loss (Article 1344-1 of the Civil Code).
• It transfers the risks on a thing to be delivered (Article 1344-2 of the Civil Code).
• It prepares the termination of the contract. In the event of serious non-performance, you may terminate the contract by notification, but you must in principle first give the debtor formal notice (Articles 1224 and 1226 of the Civil Code). If the contract contains a termination clause (clause résolutoire), the formal notice triggers it only if it expressly mentions that clause (Article 1225).

Formal notice or simple reminder?

This is an essential distinction. A reminder is an informal prompt: it has no legal consequences. A formal notice requires a sufficiently clear and firm demand — the words "mise en demeure" appear in it, and the obligation and the time limit are specified. Only the latter triggers the effects above.

How to write it: form and particulars

No particular form is required, but a registered letter with acknowledgement of receipt (lettre recommandée avec accusé de réception, LRAR) is strongly advised: it proves the sending, the content and the date. A complete formal notice contains:

• your contact details and those of the recipient, and the date;
• the precise reminder of the obligation (reference to the contract, the invoice, the facts);
• the explicit formula "I hereby give you formal notice to…";
• a reasonable time limit for performance;
• the consequences of failure (interest, termination, referral to the judge);
• your signature.

An official template for a formal notice letter, published by the Institut national de la consommation, is available on service-public.gouv.fr.

A step sometimes mandatory before the judge

The formal notice fits into an amicable logic that the law encourages — and sometimes imposes. For many small disputes, an attempt at amicable resolution is mandatory before referring the matter to the judge, on pain of inadmissibility. Article 750-1 of the Code of Civil Procedure, in force in 2026, requires it where the claim:

• seeks payment of a sum not exceeding 5 000 €, or
• concerns a neighbour conflict (including abnormal neighbourhood disturbance).

This attempt may take the form of a conciliation, a mediation or a participatory procedure. Exceptions exist (urgency, legitimate reason…).

After a formal notice that has gone unanswered

If nothing moves, several routes open up, most of them free or low-cost:

• the conciliator of justice, a volunteer third party whom you can approach directly and free of charge;
• the amicable methods to avoid a trial (conciliation, mediation, participatory procedure);
• for a certain debt, the order for payment, a simplified procedure without a hearing.

Whether it is a consumer, neighbour or family dispute, the strength of a file rests on the written and dated record of the facts: what was requested, when, and left unanswered. Recording this timeline as it unfolds — see our guide Keeping a timeline of events — is one of Aridelle's uses.

For any individual situation, a point-justice, a conciliator of justice or Allô Service Public (3939) can guide you free of charge.

Further reading

• Template for a formal notice letter (service-public.gouv.fr, R31676)
• The conciliator of justice (service-public.gouv.fr, F1736)
• Our related guides: The order for payment · The conciliator of justice · Keeping a timeline of events