Key takeaways
- State the facts, what you’re owed and the legal basis, then give a clear deadline.
- Stay factual and polite: the letter may be read by a judge later.
- Send it in a way that proves delivery: registered mail with acknowledgment, or email with a read receipt plus another trace.
- Say what you’ll do if the deadline passes, and then do it.
A formal demand letter (called a mise en demeure in French-speaking countries, a letter before action in the UK) is a written, final request to someone who owes you something: money, a repair, a refund, the return of a deposit. In many legal systems, it’s an expected step before going to court, and sometimes it starts interest running or proves the other side was warned. Most importantly, it often works on its own.
What to include
- Your details and the recipient’s, the date and place.
- A clear subject line: “Formal demand: return of rental deposit”.
- The facts, briefly and in order: the contract or purchase, what went wrong, previous requests and answers.
- What you ask: an exact amount, a repair, a replacement, a document.
- The basis: the contract clause, the guarantee or the law you rely on, if you know it.
- A deadline, reasonable and precise (for example 8 or 15 days from receipt).
- The consequence: what you’ll do if nothing happens (mediation, consumer authority, court).
- Attachments: list the copies you include (never send originals).
- Your signature.
Tone: firm, factual, polite
Write as if a judge will read it, because one might. Avoid insults, threats you can’t carry out and emotional language. Short sentences, dates and amounts are more persuasive than long explanations. Our /blog/how-to-write-a-factual-statement/ guide explains how to describe facts neutrally.
Template you can adapt
Subject: Formal demand, [subject]
Dear [name],
On [date], [describe the contract, purchase or agreement]. On [date], [describe the problem]. I contacted you on [dates] by [means], without a satisfactory answer.
Under [clause / guarantee / law], I hereby formally ask you to [precise request, amount] within [number] days of receiving this letter.
Without a response within this deadline, I will [refer the matter to the competent mediator / consumer authority / court] without further notice.
Please find enclosed copies of: [list].
Yours sincerely, [name, signature]
How to send it
Use a method that proves the letter was received and when: registered mail with acknowledgment of receipt, a bailiff in serious cases, or email if your contract or local practice accepts it, keeping proof of sending and any reply. Keep a full copy of what you sent.
After the deadline
If you get a satisfactory answer, confirm the agreement in writing. If not, take the step you announced. Sending demand after demand without action weakens your position. For specific disputes, see /blog/landlord-wont-return-deposit/ and /blog/consumer-rights-refund-defective-product/.
Chameleon AI can draft documents such as a factual statement or a draft complaint from your incident’s evidence and report, which you can review, edit and export as a PDF before sending.
Frequently asked questions
Do I need a lawyer to send a formal demand letter?
No. Anyone can send one. A lawyer’s letter carries more weight in some situations, but a clear, factual letter from you is often enough for everyday disputes.
Is an email enough?
Sometimes, but registered mail is safer because it proves receipt. If you use email, keep proof of sending and any reply, and check what your contract or local rules accept.
How long a deadline should I give?
Long enough to be reasonable, often 8 to 15 days for a payment or refund, longer for complex repairs. Some laws or contracts set a minimum; check them.
General information to help you get organised, not legal advice. Procedures and numbers can change: confirm them with the office concerned, and in danger call your local emergency number first.
