Mise en demeure: Definition, Effects and Deadlines (Demand Letter)

A mise en demeure, called a demand letter or formal notice in English, is the formal written demand by which one person (the creditor) requires another (the debtor) to perform an obligation: pay an amount, carry out work, stop a behaviour, honour a contract. It sets out the facts, fixes a precise deadline for compliance and announces the remedies that will be pursued otherwise. In Quebec, it puts the debtor in default within the meaning of articles 1594 and 1595 of the Civil Code of Québec, which require that it be in writing and allow sufficient time to comply.

Definition · Locato glossary, Quebec law

What this term means

A mise en demeure is not a lawsuit: it is an extrajudicial demand, meaning a step taken outside the courts. It is most often the preliminary step before legal remedies: before applying to the Tribunal administratif du logement or the Small Claims Division, you first put the other party in default and give them a chance to fix the situation. Its legal effects are concrete: it officially marks the debtor's default, serves as the starting point for calculating certain interest and damages, and demonstrates the sender's good faith in offering a last chance to settle the dispute amicably.

Its form is governed by article 1595 of the Civil Code: the demand must be in writing and allow sufficient time to comply given the nature of the obligation. In practice, a complete letter contains the date, the identification of the parties, a factual summary of the problem, the precise demand (amount, work, behaviour to stop), the deadline granted (often 10 days), the notice "sous toutes réserves" (without prejudice) and a signature. You do not need to be a lawyer: anyone can write and send their own demand letter.

How the letter is sent matters as much as what it says. To prove the letter was transmitted and received, use a method that leaves a record: registered mail, a bailiff, hand delivery with acknowledgement, or certified email that produces timestamped proof of receipt consistent with Quebec's LCCJTI. If the deadline expires without a satisfactory response, the file is ready for the next step: an application to the competent tribunal, with the demand letter and its proof of receipt as the key exhibits. Many disputes, however, settle at this stage without ever reaching a judge.

What it means for you

If you are the sender

Before sending your demand letter, make sure it covers the essentials: the facts, the precise demand, the deadline, the announcement of remedies and your signature. Stay factual and professional: a judge may read the letter, and a measured tone serves your credibility. A template grounded in the relevant Civil Code articles helps you cover every required element.

Keep a copy of the letter and proof of its receipt: those two documents are what will give your file its force if the recipient fails to act within the deadline. Without proof of receipt, the recipient can simply claim they never received your demand.

If you are the recipient

Receiving a demand letter is neither a conviction nor a formal accusation: it is a demand giving you a deadline to correct a situation before a possible legal remedy. Do not ignore it. Read what is being asked, verify the facts and reply in writing within the deadline, even if you dispute the claims: your reply becomes part of the file and demonstrates your good faith.

If the demand seems unfounded, explain why, with supporting documents. If it is founded in whole or in part, fixing the situation or proposing an agreement almost always costs less than a hearing. If in doubt about your obligations, a one-off legal consultation can clarify your position before the deadline expires.

Related articles

• Sous toutes réserves: Meaning of the Notice (Without Prejudice)
• Article 1595 C.c.Q.: Written Form of an Extrajudicial Demand
• Article 1597 C.c.Q.: Debtor in Default by Operation of Law
• Article 1601 C.c.Q.: Specific Performance of the Obligation
• Article 1604 C.c.Q.: Resolution or Resiliation of the Contract for Non-Performance