An employee on sick leave who receives a payslip identical to that of a normally worked month: this situation is more common than one might think. The error often arises from a discrepancy between the salary maintenance paid by the employer and the daily social security allowances (IJSS) received concurrently. When the payroll department regularizes, the employee discovers that they must repay a sometimes significant amount. The legal framework governing this recovery protects both parties, but its mechanisms remain poorly understood.
Subrogation and salary maintenance: the mechanism that generates overpayment
The majority of overpayments related to sick leave originate from subrogation. When the employer maintains the salary during the absence, they directly receive the IJSS paid by the CPAM instead of the employee. The problem arises when the amount of IJSS received by the employer is less than the maintained salary, or conversely, when the salary is fully maintained while the IJSS already cover part of the remuneration.
A rarely detailed point deserves attention: the employer can never retain IJSS beyond the salary actually maintained. Subrogation is capped. If the daily allowances exceed the amount of the conventional salary maintenance, the excess goes to the employee. Case law confirms this principle, and any deduction that goes beyond this would constitute unjust enrichment for the employer.
The payroll error can also stem from an early return to work. Under Article L323-6-1 of the Social Security Code, the employer practicing subrogation must declare the effective return to the Health Insurance (via the DSN or a certificate). A late report leads to the continued payment of IJSS even though the employee has already returned to their position. The overpayment during sick leave then results from an undue accumulation between the return salary and daily allowances.
Deductions for overpayment: the legal limits to know
The employer who notices an overpayment has the right to recover it. This right is based on the principle of the repetition of the undue, as provided by the Civil Code. The employee cannot refuse repayment on the grounds that they have already spent the amount or that they are not responsible for the error.
However, recovery is strictly regulated. The Labor Code imposes a maximum deduction of one-tenth of the net salary due per pay period. The employer cannot deduct the entire amount at once, even if the employee earns a modest salary. This one-tenth rule protects the employee from a harsh deduction that would jeopardize their livelihood.
In practice, the deduction works as follows:
- The amount of the overpayment is calculated and notified to the employee, ideally in writing with details of the error (concerned period, difference between the maintained salary and the actual IJSS due).
- Each month, the employer deducts a maximum of one-tenth of the net salary until the debt is fully settled.
- The employee can negotiate a different payment schedule, but the agreement must remain voluntary. No pressure is allowed.
The limitation period for claiming an overpayment is three years from the day of the undue payment. Beyond that, the employer loses their right to recovery. This period runs even if the error was only detected late by the payroll department.
Disputing the salary overpayment: situations where the employee can object
Repayment is not always automatic. Several situations allow the employee to contest the employer’s claim, in whole or in part.
The first concerns the limitation period. If the employer requests repayment for an error made more than three years ago, the claim is time-barred and the employee has no obligation to pay. The Labor Code (Article L3245-1) sets this framework unambiguously.
The second concerns the calculation itself. The employee has the right to demand a precise breakdown: amount of the maintained salary, amount of IJSS received by the employer via subrogation, exact concerned period. If the employer does not provide this detail, the dispute is legitimate. A registered letter requesting complete justification of the overpayment constitutes a first step before any escalation.
Third case: the deduction exceeds one-tenth of the net salary. If the employer deducts more without the employee’s written agreement, the latter can take the labor court to have the irregularity recognized and obtain the return of the excess deducted.
Tax impact of an overpayment refunded in the following year
An often-overlooked aspect concerns income declaration. The refunded overpayment must be deducted from the taxable income of the year of repayment, not the year of receipt. If the employee received an overpayment in December and repays it in February of the following year, their tax declaration for the year of receipt includes an excessively high income.
The employee must then ensure that their employer corrects the amount of net taxable income reported to the tax administration. If the correction is not made automatically, a claim to the tax service allows for a tax relief.
Early return and DSN declaration: an underestimated risk of overpayment
The dematerialization of payroll via the DSN (nominative social declaration) has simplified exchanges between employers and social organizations, but it has also created new risks of error. When an employee returns to work before the scheduled end date of their leave, the employer must report this return without delay.
A late report in the DSN prolongs the payment of IJSS while the employee is already receiving their normal salary. The CPAM can then demand the repayment of wrongly paid allowances, either directly from the employee (in the absence of subrogation) or from the employer (in the case of subrogation). The employer also exposes themselves to an administrative financial penalty for late declaration.
This scenario illustrates a friction zone between labor law and social security law. The employee may find themselves solicited by two distinct creditors (employer for the salary overpayment, CPAM for the undue IJSS), each applying their own collection rules. In the event of double claims, ensuring that the same amount is not claimed twice remains the most basic precaution, and yet the most often forgotten.
