Unfair Competition: The French Supreme Court Reminds That Deontological Misconduct Is Not Everything

Analysis of a judgment Cass. com., June 3, 2026, n° 24-22.130, by Pierre-Louis Roquet, a business law attorney in Lyon.

Two employees of an accounting firm left in January 2021 and set up their own practice. About thirty clients from their former employer followed them. The regional ordre des experts-comptables (order of chartered accountants) imposed disciplinary sanctions on the new firm. The Court of Appeal of Montpellier, for its part, ordered a civil condemnation of over 136,000 euros. This was too hasty. The Commercial Chamber of the Cour de cassation (French Supreme Court), in a judgment dated June 3, 2026, published in the Bulletin, partially overturned the decision. It reiterated a rule that commercial litigation too often forgets: a breach of a professional ethical rule, on its own, does not constitute an act of unfair competition.

The case illustrates a scenario that every business law firm in Lyon regularly encounters. An employee leaves the company. They set up a competing structure. A portion of the clientele shifts. The employer, disheartened, seeks a basis for litigation. They invoke, alternatively or cumulatively, poaching of personnel, breach of contractual obligations, disorganization, misappropriation of files, and, when the profession is regulated, professional ethical misconduct. The temptation to rely solely on the latter, often the best documented thanks to the disciplinary sanction already obtained, is great. This is precisely what the Court prohibits.

The reasoning revolves around a classic principle of civil liability law: the causal link. Based on Article 1240 of the Civil Code, a breach of a professional ethical rule, the purpose of which is to define the duties of a profession and which is subject to disciplinary sanctions, constitutes an act of unfair competition through client misappropriation only if it is established that this breach caused the transfer. In other words, a disciplinary sanction does not automatically lead to civil condemnation. It must also be demonstrated that it was the ethical violation, and not the legitimate exercise of freedom to undertake, that explains the migration of clients.

The Court of Appeal had held that the collective and almost simultaneous takeover of some thirty clients, contrary to professional ethics according to the ordres' (professional bodies') circulars, was sufficient to characterize unfair competition. The Commercial Chamber responded that this reasoning was based on an erroneous premise. The trial judge must first establish the breach, then, separately, establish that it caused the transfer. The two propositions do not overlap. The number of clients taken over, simultaneity, and ordre affiliation are indicators. They do not exempt from demonstrating the causal link.

A judgment extending the 2012 decree

This decision must be placed in its context. Since Decree n° 2012-432 of March 30, 2012, the prohibition for chartered accountants to solicit clients has been removed from the code of professional ethics. It had been deemed contrary to the freedom of trade and industry. Simple solicitation is therefore no longer, as such, a fault. It only becomes wrongful when accompanied by unfair practices: disparagement, disorganization, mass poaching, use of files belonging to the former employer, targeted solicitation based on confidential information.

The Commercial Chamber extends this logic. It refuses that the ordres' circulars, which would compensate for the disappearance of the textual prohibition, serve as a substitute for civil proof. Professional bodies and civil courts pursue different objectives. The ordre ensures the collective discipline of a profession. The civil judge, for his part, decides a patrimonial dispute between two economic operators. He can only do so by focusing on the three cardinal elements of Article 1240: fault, damage, and the causal link.

What the ousted employer must prove

For a firm or company that is the victim of an employee's departure followed by client capture, the judgment outlines a method. The demonstration involves a set of converging evidence, each probative, none self-sufficient. Nature of contact with the client: initiative of the former employee or of the client themselves? Use of confidential information: files, prospect lists, contact details, billing history? Exercise of competing activity during the notice period, in disregard of the duty of loyalty? Tight chronology between the new firm's registration with the ordre and the actual departure? Written or oral solicitations whose author can be identified? Incitement to breach an ongoing contract? It is the overall picture that, in practice, allows the judge to decide.

The disciplinary sanction remains a useful element of this body of evidence. It attests to an objective breach. It does not replace civil proof.

Practical implications for Lyon businesses

This judgment is relevant to all regulated professions. The reasoning, based on Article 1240 of the Civil Code, transcends the accounting profession. It applies to lawyers, notaries, bailiffs, medical professions, real estate agents, architects. Whenever an employee or partner leaves a structure and takes a portion of the clientele with them, the same requirement of causal demonstration will apply.

This judgment also concerns unregulated businesses, as it reminds us that the burden of proof in unfair competition lies with the plaintiff, and that it covers three distinct elements, not just one. This is a useful reminder at a time when disputes concerning employee departures, particularly in the consulting, tech, and services sectors, are multiplying in the Lyon region.

Two practical lessons. For employers, prevention is paramount: auditing applicable ethical obligations, carefully drafting non-compete and non-solicitation clauses, formalizing the return of files at the end of the contract, confidentiality agreements, and reinforced duty of loyalty during the notice period. For those setting up a competing structure, traceability is the best contentious defense. Documenting client-initiated communications, avoiding any mass calling in the days following departure, and formalizing in writing any file takeover are now essential precautions.

Frequently Asked Questions

What is unfair competition through client misappropriation?

It is a wrongful act by which an economic operator appropriates clientele by resorting to practices contrary to fair trade usage. The basis is Article 1240 of the Civil Code. The plaintiff must prove a fault, damages, and a causal link between the two. This judgment of June 3, 2026, imposes this triptych even when the fault takes the form of an ethical violation.

Can I solicit clients from my former employer?

In principle, yes. Since Decree n° 2012-432 of March 30, 2012, concerning chartered accountants, and generally in the name of freedom to undertake, client solicitation is lawful. It becomes wrongful if accompanied by unfair practices: use of files belonging to the former employer, disparagement, mass poaching, disorganization. However, a contractual non-solicitation clause may prohibit this practice, provided it is proportionate and, where applicable, remunerated.

Is a disciplinary sanction sufficient to obtain damages?

No. The Commercial Chamber clearly states that professional ethical misconduct constitutes an act of unfair competition only if this misconduct caused the client transfer. Disciplinary sanctions and civil condemnations follow distinct rationales. The former is pronounced by the ordre, the latter by the civil judge.

How to prove the causal link between the breach and the transfer?

Through a body of converging evidence. Initiative of contact with the client, use of confidential information from the former employer, tight chronology between departure and registration with the new firm, exercise of competing activity during the notice period, targeted written or oral solicitations, incitement to breach an ongoing contract. No single element is decisive on its own.

Does this solution apply to professions other than chartered accountants?

Yes. The principle established by the Commercial Chamber concerns any professional ethical rule defining the duties of a profession and subject to disciplinary sanctions. In practice, it applies to lawyers, notaries, bailiffs, medical professions, real estate agents, and architects.

How to secure the departure of a key employee?

Prevention is key. A proportionate and remunerated non-compete clause, a non-solicitation clause targeted at clients, a formalized exit procedure (return of files, written confidentiality agreement, reinforced duty of loyalty reminded during the notice period) form the foundation. A regular audit of contracts and applicable ethical rules complements this framework. For a Lyon firm or company, support from a business law attorney helps to anticipate litigation, rather than suffer it.

Sources

• Judgment commented: Cass. com., June 3, 2026, n° 24-22.130, published in the Bulletin (Partial Cassation)
• Article 1240 of the Civil Code (extra-contractual liability)
• Decree n° 2012-432 of March 30, 2012, relating to the exercise of the activity of chartered accountant (JORF n° 0078 of March 31, 2012)