OD FLASH | A bonus paid by mistake systematically over a period of years becomes a contractual element of the employee’s remuneration

Cass. Soc., December 4, 2024, no. 23-19.528

The principle that error cannot create rights does not always apply to relations between employee and employer.

In this case, an employer paid an employee a conventional supplementary allowance (seniority bonus) constantly from 1994 to 2024, even though the employee had not reached the level of remuneration required by the collective bargaining agreement.

In 2015, the employer stopped paying this seniority bonus, realizing that the employee did not fill the conditions set out in the collective bargaining agreement.

The employee then brought a claim before the labor Court, seeking reinstatement of the seniority bonus and payment of back pay for this bonus.

The Versailles Court of Appeal dismissed the employee’s claims, ruling that the employer could rectify its twenty-year-old error of granting an employee a conventional seniority allowance that was not due.

 The Supreme Court (Cour de cassation), on December 4, 2024, overturned the decision of the Versailles Court of Appeal, holding that “the additional allowance for seniority had become an element of the employee’s remuneration by its systematic payment by the employer from 1994 to 2014, independently of any contractual condition of attribution”.

This solution, while not new, calls on employers to make their payroll practices more secure.

Indeed, the Social Chamber had already adopted this position in a decision dated December 13, 2023 (Cass. Soc., December 13, 2023, no. 21-25.501). In the 2023 case, a payroll software parameterization error had resulted in the undue payment of a bonus to all employees over a seven-year period.

Furthermore, employers should always keep in mind that, under certain conditions, favorable practices to employees may constitute a use practice, which the termination of requires following a specific denunciation procedure.

The systematic nature of the bonus over several years is a decisive condition in this decision to contractualize this element of remuneration. It is therefore advisable to carry out frequent checks on the remuneration actually paid to employees, in order to rectify any mistakes practices in good time.