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Practical guide · Supplier disputes Dispute with a supplier: what should you do before sending a formal notice (mise en demeure)?

Defects, delays, incomplete services: the seven steps to assert your rights, from evidence to mediation.

Practical guide · Matsu Conseil · updated 14 October 2026

Defects, delays, incomplete services: a dispute with a supplier is won first on evidence and deadlines. Here are the steps, from receipt of the goods to the formal notice.

1. Report quickly, and in writing

As soon as the goods arrive, record precise reservations noted on delivery (réserves), then confirm them in writing within the time limit set by the contract or the supplier's terms and conditions. A defect reported too late is much harder to get acknowledged.

2. Keep the evidence

  • Dated photos, samples, packaging, batch labels.
  • Goods received notes with reservations, inspection reports, formal reports.
  • Written exchanges with the supplier.

If you need evidence that will stand up in court, have a commissaire de justice (court bailiff) draw up an official report (constat).

3. Review what was promised

Order, specifications, technical requirements, service commitments, agreed penalties: compare them point by point with what was delivered. For the legal interpretation of the clauses, rely on your lawyer.

4. Quantify the loss

Cost of rework and sorting, production delays, penalties paid to your own customers, lost hours, additional transport. Each item must be backed by a supporting document.

5. Open the discussion

A meeting, factual and backed by figures, settles many disputes: credit note, replacement, rework, discount on future orders. Keep a written record of what is agreed.

6. Formalise the claim

If the discussion goes nowhere, send a written, reasoned claim by registered letter with acknowledgement of receipt (lettre recommandée avec accusé de réception): the facts, the discrepancies, the quantified loss, what you are asking for and by when.

7. Mediation, then formal notice

The Médiateur des entreprises (the French business mediation service), a free and confidential public service, helps settle commercial disputes amicably. If nothing comes of it, the formal notice, and then legal action, should be prepared with a lawyer.

Withholding a payment? It is risky: suspending your own obligations is only permitted under certain conditions and in a proportionate way. Ask a lawyer for advice before doing so.

Good to know: this guide is for information only and does not replace legal advice tailored to your situation. If the stakes are high or proceedings are involved, consult a lawyer.

Frequently asked questions

Frequently asked questions

Short answers to the questions most often asked on this topic.

How do you prove that a delivery is non-conforming?

Through written reservations on receipt, dated photos, inspection reports, retained samples and, if the stakes justify it, an official report drawn up by a commissaire de justice. Comparing the delivery with the order and the specifications does the rest.

What is the Médiateur des entreprises?

A free and confidential public service that helps businesses resolve a commercial dispute amicably, without going to court.

Do you need a lawyer for a formal notice?

It is not compulsory, but it is recommended as soon as the stakes are high or proceedings are being considered: the formal notice lays the groundwork for what follows, and its wording matters.

Contact

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