A core rule of French employment law is non bis in idem, meaning that an employee cannot be sanctioned twice for the same misconduct.

In a recent decision, the French Supreme Court provided useful guidance on what can be considered a sanction under French law.


The underlying decision relates to a claim filed by an employee challenging their dismissal. The employee argued that their dismissal was null and void since they had already been sanctioned for the same misconduct.

In fact, the employer had already warned the employee about the misconduct (refusal to follow guidelines, critical emails, and statements) by a letter also asking the employee to adapt their behavior.

The Court of Appeal agreed with the employee’s argument. It considered that both the warning letter and the dismissal were null and void and awarded the employee damages. The employer challenged this decision, considering that the letter sent to the employee did not amount to a sanction since it only invited the employee to adapt their behavior.


The French Supreme Court upheld the Court of Appeal’s decision and noted that the warning letter did amount to a sanction for the employee’s behaviour, which was qualified as misconduct.

The dismissal was therefore necessarily deprived of any ground since it was based on the same misconduct.

French Supreme Court – 29 May 2024, nr. 22-19313