A breach of professional conduct rules is not enough to establish unfair competition through misappropriation of clients. The commercial chamber so held on 3 June 2026, on the basis of Article 1240 of the French Civil Code: the court must find that the breach of the profession's rules caused the alleged transfer of clients. A disciplinary sanction imposed by the professional body does not dispense with that demonstration of causation.
The key points
- A breach of a rule of professional conduct amounts to an act of unfair competition through misappropriation of clients only where it is established that it caused the alleged transfer of clients.
- A rule of professional conduct is defined as one that sets out the duties of the members of a profession and is backed by disciplinary sanctions.
- A disciplinary sanction imposed by the professional body is not, in itself, enough to justify an award of damages in civil proceedings.
- A claimant alleging misappropriation of clients must demonstrate the link between the wrongful conduct complained of and the clients' actual departure.
- Circulars of a professional body describing the group takeover of clients as unethical do not turn that conduct into automatic civil fault.
Two employee departures and a group takeover of clients
The commercial chamber partly quashes the court of appeal's decision: the lower court judges could not infer unfair competition from the breach of professional conduct rules alone, without finding that it had caused the transfer of clients (Com., 3 June 2026, No. 24-22.130). A salaried chartered accountant and a branch manager, both employed by an accountancy firm, resigned in October 2020, with effect in January 2021. Together with a holding company wholly owned by the chartered accountant, they set up a new accountancy company. That company was registered with the Ordre des experts-comptables on 7 November 2020, with effect from 15 January 2021.
The original firm accused the newly created company of misappropriating part of its client base and brought unfair competition proceedings against it. The court of appeal (CA Montpellier, 8 October 2024, No. 23/00631) ordered the new company to pay damages. It held that the transfer of files carried out in disregard of the profession's conduct rules was enough to establish unfair competition, relying on the circulars of the Ordre and on a disciplinary sanction imposed by the regional disciplinary chamber (chambre régionale de discipline).
The commercial chamber overturns that reasoning, citing Article 1240 of the French Civil Code and imposing a requirement of causation (free translation):
It follows from that provision that a breach of a rule of professional conduct, the purpose of which is to set out the duties of the members of a profession and which is backed by disciplinary sanctions, constitutes an act of unfair competition through misappropriation of clients only where it is established that that breach caused the alleged transfer of clients.
The Cour de cassation (France's highest civil court) criticises the court of appeal for having inferred the existence of acts of unfair competition from the breach of professional conduct rules alone, without making that finding. The quashing is partial: it concerns the award of damages, the court costs and Article 700 of the French Code of Civil Procedure, with remittal to a different court of appeal. The other complaints were not examined.
What a firm alleging misappropriation of clients must prove
A claimant cannot simply produce a disciplinary sanction: it must show that the breach of professional conduct rules caused the clients to leave. The distinction between two types of liability is clear. Professional discipline sanctions conduct by reference to the duties of the profession. Civil liability requires fault, damage and a causal link between the two. A reprimand or a warning issued by a disciplinary chamber establishes the first element, never the other two.
In practical terms, the required proof concerns the mechanism of the departure. It is not enough to observe that thirty or forty clients left the firm within the same few weeks. That departure must be linked to the conduct complained of: for example, the absence of a compensation agreement with the predecessor must have determined the transfer, and not merely have accompanied it. A client base that leaves because it is attached to the professional personally does not necessarily stem from the breach of professional conduct rules.
The ruling matters for all regulated professions with a code of professional conduct backed by disciplinary sanctions. The wording of the decision is general: it refers to a breach of a rule of professional conduct, defined by its purpose and by the fact that it is disciplinarily sanctioned, without confining its scope to accountancy.
What the decision confirms and what remains to be decided
The decision affirms the autonomy of civil liability from professional discipline, without ruling out that a breach of professional conduct rules may support an award where its causal role is established. The quashing is for lack of legal basis, not for an absolute error of principle. The court to which the case is remitted may therefore find unfair competition, provided that it identifies how the breach caused the files to be transferred.
The court of appeal had taken the opposite view: it held that the infringement of the conduct rule was in itself an act of unfair competition and a misappropriation of clients. It dismissed as ineffective the statements from clients asserting that they had freely chosen to follow the former employees. It is precisely that refusal to engage with the debate on the real causes of the departure that the commercial chamber censures.
The question of the other grounds of unfairness relied on in this type of dispute remains open: canvassing during the performance of the employment contract, use of information obtained as an employee, disruption of the original firm. The decision does not settle them. Nor does it examine the other complaints in the appeal to the Cour de cassation, since the quashing is granted on the first limb of the first ground of appeal.
What evidential steps for the ousted firm and for the departing professional
The dispute is won on causation, and therefore on the documents recording the clients' behaviour at the time of the departure. For the firm that considers itself the victim, the disciplinary sanction remains useful: it establishes the breach. It must, however, be accompanied by evidence showing that the breach determined the terminations (résiliations), and not merely that it preceded them.
For the professional who leaves and sets up their own practice, the evidential stakes are symmetrical. Evidence establishing the clients' own initiative – spontaneous approaches, pre-existing personal attachment, absence of solicitation during the notice period – becomes central. It does not remove the professional conduct complaint, which is a matter for the professional body, but it deprives the civil complaint of its causal underpinning.
One final point deserves attention: the circulars of the professional body and codes of professional conduct set out professional duties. They do not, in themselves, create a regime of automatic civil liability. Relying on them before the commercial court requires full proof of fault, damage and the link between the two.
The checks to carry out before bringing proceedings
- Identify, client by client, what triggered the termination: solicitation, information received, or the client's own initiative.
- Keep the correspondence exchanged on the transfer of files and on compensating the predecessor, which documents the chronology of the breach.
- Do not base the claim for damages on the disciplinary decision alone, which establishes the breach but not its effect on the client base.
- Quantify the damage on the clients whose departure can be attributed to the conduct complained of, not on all the losses recorded over the same period.
- Check whether other complaints of unfairness, distinct from the breach of professional conduct rules, can be established and proved independently.
Frequently Asked Questions
Is a disciplinary sanction enough to obtain damages for unfair competition?
No. Under the commercial chamber's decision of 3 June 2026, a breach of a rule of professional conduct amounts to an act of unfair competition through misappropriation of clients only where that breach is shown to have caused the alleged transfer of clients. A disciplinary sanction proves the professional breach. It proves neither the civil damage nor the causal link between the wrongful conduct and the clients' actual departure.
Can an accountant who leaves a firm take clients from their former employer?
Taking over clients remains possible, but it carries two distinct risks. On the disciplinary side, the profession's rules impose duties towards the predecessor colleague, in particular as regards information and compensation arrangements. On the civil side, an award of damages presupposes that the breach of professional conduct rules caused the transfer of clients. The decision of 3 June 2026 requires the court to find that causal link before making any award.
What must a firm prove when clients leave with a former employee?
Three cumulative elements. First, fault, which may lie in a breach of the profession's rules or in unfair methods. Second, damage, quantified on the clients actually lost. Third, a causal link between the two. The decision of 3 June 2026 quashes a court of appeal ruling that had inferred unfair competition from the breach of professional conduct rules alone, without checking that it had triggered the clients' departure.
Can a client freely follow the professional who leaves the firm?
The client's free choice of adviser is a general principle. A client may therefore, in principle, decide to entrust their files to the professional who sets up on their own account. That free choice is an important line of defence for the departing professional: where the move results from the client's own initiative, the link between any professional breach and the transfer becomes harder to establish before the court.
Is a group departure of clients enough to establish unfair competition?
No. In principle, freedom of trade allows a former employee who is not bound by a non-compete clause to carry on a competing business and to take on clients. Unfair competition requires clearly established wrongful conduct, distinct from mere competition, and a demonstrated link with the loss of clients. Simultaneous departures are an indication, never sufficient proof in themselves.