Lawyer's Duty to Advise: Extended Liability for Any Potential Debtor

You are the owner of a commercial property in Gravelines, and your tenant has just told you that he will not renew his lease. You think you have lost a source of income, and you consult a lawyer to obtain compensation. But what happens if your lawyer forgets to bring all the persons who may be liable into the proceedings? This apparently technical question has been decided by the Court of Cassation in a judgment of 14 May 2025, which redefines the scope of the lawyer's duty to advise.

Under Article 412 of the Code of Civil Procedure, the lawyer who represents you in court has a duty to advise. How far does this duty go? The high court has just clarified that it includes the obligation to bring into the proceedings any potential debtor of the compensation, as soon as the lawyer is instructed to obtain compensation for damage. In practical terms, if your lawyer fails to sue a person who may also be liable, it is the lawyer who may be required to compensate you.

In this case, a couple had concealed from their lawyer that the commercial lease was not going to be renewed. The lawyer, who drafted the assignment deed, had not brought the assignor into the proceedings, which led to a loss. The Court of Cassation overturned the court of appeal, referring the case to the Rennes Court of Appeal. A decision that reminds lawyers of their duty of vigilance, but also clients of their duty of transparency.

The facts: a story like many everyday ones

Mr and Mrs Y are owners of a commercial property in Dunkirk. They entrust their lawyer with drafting a deed of assignment of their commercial lease. But they fail to reveal to him that the lease is not renewable at its expiry. The purchaser, who thought he was acquiring a sustainable business, finds himself without a lease a few months later. He then brings an action for liability against the sellers and their lawyer, claiming that the latter should have informed him of the risk of non-renewal.

The case is brought before the commercial court, then on appeal. The Y couple argue that they did not conceal the information, but the trial judges dismiss their claim. The Douai Court of Appeal initially orders the sellers to compensate the purchaser. But it exonerates the lawyer, holding that his duty to advise did not oblige him to check the situation of the lease. The purchaser appeals to the Court of Cassation.

The Court of Cassation, in its judgment of 14 May 2025, sets aside the decision of the court of appeal. It recalls that the lawyer, under Article 412 of the Code of Civil Procedure, must advise his client on all potential debtors of the compensation. In this case, the lawyer should have brought the assignor of the lease, who was a potential debtor, into the proceedings. The court of appeal to which the case is referred, in Rennes, will have to rejudge the case on this point.

The reasoning of the court — dissected

The Court of Cassation relies on Article 412 of the Code of Civil Procedure, which defines the lawyer's mission of legal assistance. This text imposes on the lawyer a duty to advise, which is not limited to the ongoing proceedings. He must, within the framework of his mission, identify all potential persons liable for the damage suffered by his client and bring them into the proceedings. It is an obligation of means, but a reinforced one: the lawyer must be proactive.

In this case, the trial judges had considered that the lawyer did not have to know the situation of the lease, because it was not part of his mission. But the Court of Cassation contradicts them: as soon as the lawyer is instructed to draft an assignment deed, he must verify the essential elements, such as the duration of the lease. If he does not do so, and his client suffers a loss, his liability may be incurred.

This decision confirms a recent jurisprudential trend, which extends the lawyer's duty to advise. It does not create a reversal, but clarifies the contours of this duty in the context of commercial leases. The judges remind that the lawyer is a legal professional, bound by an increased duty of vigilance. For clients, this is an additional guarantee: you can expect your lawyer to anticipate risks, even those you have not reported to him.

What this changes for you — practically

If you are a landlord in Dunkirk or Gravelines, this decision protects you. You can now require your lawyer to check all aspects of your file, including information you may not have communicated to him. For example, if you sell your business, your lawyer must ensure that the lease is renewable and, if not, inform you of the consequences. If he does not do so, he could be required to compensate you.

For tenants or purchasers, it is also an advantage: you can take action against the seller's lawyer if he has failed in his duty to advise. Imagine you buy a commercial property in Gravelines for €150,000, and the lease is not renewed a year later. You lose your investment. If the seller's lawyer did not check the situation, you can sue him for liability.

However, be careful: this duty does not relieve the client of his duty of loyalty. If you deliberately conceal information from your lawyer, as Mr and Mrs Y did, you could see your own liability engaged. The Court of Cassation reminds this: transparency is essential. In practice, if you are in a similar situation, you must provide all documents relating to the lease, and your lawyer must analyse them.

Four tips to avoid this type of dispute

• Choose a lawyer specialising in commercial leases. In Dunkirk or Gravelines, not all lawyers master the subtleties of commercial law. A specialist will know how to identify the risks related to lease renewal.
• Provide all documents. Before signing an assignment deed, give your lawyer the entire lease, any amendments, and any correspondence exchanged with the tenant. Do not hide anything, even if the information seems unfavourable to you.
• Demand a written report. Ask your lawyer for a summary note on the identified risks. If a problem arises, you will have proof of his advice – or lack thereof.
• Check the mandatory clauses. In a lease assignment deed, the remaining term and the conditions of renewal must be specified. If this is not the case, refuse to sign until you have obtained an explanation.

Further reading: related case law and developments

This decision follows in the line of the Court of Cassation judgment of 10 July 2019 (No. 18-15.674), which had already extended the lawyer's duty to advise to the tax consequences of a transaction. In that case, the lawyer had failed to inform his client of the transfer duties, and his liability was upheld. Here, the Court goes further by including the obligation to bring any potential debtor into the proceedings.

But be careful: this case law does not make the lawyer a universal insurer. If the client is acting in bad faith or conceals information, his own liability may be engaged. The tendency of the courts is to seek a balance between the professional's duty to advise and the client's loyalty. In the future, we can expect lawyers to strengthen their preliminary questionnaires and limitation of liability clauses.

Checklist before acting

FAQ: everything you need to know

• Can I sue my lawyer if he did not check the lease? Yes, if you demonstrate that he failed in his duty to advise. You must prove the loss (e.g., loss of rental income) and the causal link.
• What is the time limit for taking action? An action for liability against a lawyer is time-barred after 5 years from the discovery of the damage (Article 2225 of the Civil Code). Note: this period runs from the moment you know that the lease is not renewed.
• Do I have to prove that the lawyer knew the lease was non-renewable? No, it suffices to show that he should have known it by consulting the documents you provided to him.
• What if my lawyer refuses to compensate me? Seize the competent judicial court (the one where the lawyer practises). You can also file a complaint with the president of the Bar.
• Can I take action against the seller if the lawyer was at fault? Yes, the seller remains liable for latent defects. But the lawyer may be jointly and severally liable with the seller.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →