Correcting a payroll error: overpayment, back pay and procedure 2026

A variable entered twice, an incorrect collective bargaining rate, a duplicate transfer to the wrong account: payroll errors are among the most common corrections an employer faces. They are also among the riskiest to mishandle. Recovering an overpayment without following the correct deduction rules exposes the employer to labour tribunal proceedings; leaving back pay outstanding exposes it to a court order and late-payment interest.

This article sets out the correction procedure, the legal limits on deductions, the difference between an overpayment and a salary advance, and the declaration steps. For a detailed reading of the payslip lines involved, see understanding a payslip. For the broader payroll compliance framework, our payroll management service covers these obligations.

An overpayment is an undue amount recoverable under Article 1302-1 of the Civil Code, but the deduction from future salaries is governed by law: absent the employee's written agreement, the employer cannot freely offset against wages — it is bounded by the attachable wage portion rules (Articles L3252-2 and R3252-2 of the Labour Code). Conversely, an omission that harms the employee is corrected by back pay, subject to contributions and withholding tax. In both cases, the right to claim is time-barred after three years (Article L3245-1) and the correction requires a corrective payslip and, where applicable, a corrective DSN.

The employer who has paid more than was owed retains the right to recover: its error does not deprive it of the right to repetition of the undue payment (Article 1302-1 of the Civil Code). This right is exercised within a strict framework.

Inform first, deduct second#

The first step is always written notice to the employee: amount of the overpayment, nature of the error, period concerned. This notice is not a formality — it is the central document in any dispute. An employee who discovers an unexplained deduction on their payslip has all the grounds to bring a claim before the labour tribunal (conseil de prud'hommes).

The deduction limit: attachable wage portion, not a flat 10%#

A commonly misunderstood point deserves clarification. The deduction the employer may make unilaterally on the salary to recover an undue payment is not capped at a flat 10% of net pay: it is bounded by the attachable wage portion (quotité saisissable) as defined in Articles L3252-2 and R3252-2 of the Labour Code.

The attachable wage portion is a progressive scale set by decree, calculated on the annual net remuneration after contributions. It represents the fraction of the salary that may be subject to attachment or assignment — and, by extension, to unilateral set-off by the employer in the absence of the employee's agreement. For lower-wage employees, the attachable fraction is very low or even nil; it increases in brackets as remuneration rises.

Annual scale set by Decree no. 2025-1299 of 24 December 2025 (R3252-2 Labour Code), in force from 1 January 2026; revalued each year.

The limit is therefore variable depending on salary level. For a minimum-wage employee, the attachable fraction is very small; for a senior manager, it is higher. In practice, for a mid-range salary, the monthly amount recoverable without agreement remains modest — which makes proposing a repayment schedule even more valuable.

The written agreement: the most secure route#

A signed, dated written agreement from the employee — specifying the total amount and the repayment calendar — releases the employer from the attachable-wage-portion constraint and allows a faster, mutually agreed recovery schedule. This agreement must be freely given and informed: do not propose it under pressure or in circumstances that could be characterised as coercion.

The legal distinction matters because the recovery rules differ.

A salary advance — an amount paid in anticipation before the corresponding work is performed — is subject to its own statutory cap: the deduction may not exceed one tenth of net salary (Article L3251-3). This is more protective for the employee than the attachable portion at higher salary levels.

A salary instalment (acompte), by contrast, corresponds to an amount already earned but paid before the usual pay date. Recovering it on the next payslip is straightforward, provided the payslip is correctly drawn up. See our article on the salary advance and instalment rules for the full distinction.

No, not freely. Unilateral set-off is governed by law. Outside the play of the attachable wage portion, any unjustified deduction constitutes a breach of the obligation to pay wages — which may give rise to an employee's restitution claim or even a constructive dismissal action if the deduction is significant.

A written agreement therefore remains the employer's strongest protection when seeking a swift, conflict-free recovery of an overpayment.

Not legally required, but strongly advisable. Without agreement, the employer may deduct, month by month, the fraction corresponding to the attachable wage portion. With a written agreement, the employer can recover more quickly and a larger amount each month, without any risk of challenge.

French employment case law is consistent: an employer who deducts beyond the attachable wage portion, even to recover a genuine overpayment, commits a legal fault. The labour tribunal may then order restitution of the excess amounts deducted.

Salary claims are time-barred after three years from the day the claimant knew or ought to have known the facts enabling the action (Article L3245-1 of the Labour Code). This limitation is symmetrical:

• The employer has three years to claim repayment of an overpayment.
• The employee has three years to claim unpaid back pay.

Acting promptly is the best strategy, not only to respect this deadline, but also because an error corrected within the month of discovery is far simpler to explain to the employee and to correct in the DSN.

When the error harms the employee — forgotten variable, overtime rate not applied, incorrect collective agreement classification — the correction takes the form of back pay. This back pay:

• appears on the payslip in an identifiable rule (e.g. "back pay", "overtime back pay", etc.);
• is subject to all social contributions like ordinary salary;
• carries the employee's personal withholding tax rate;
• must be paid without undue delay — a systematic pre-payment check on monthly payroll variables prevents repeated omissions.

If the back pay covers several prior months, it may be consolidated on a single payslip. Note: a large back-pay item may trigger URSSAF scrutiny if contribution bases appear inconsistent with previous months — retain all supporting documents.

Every payroll correction — overpayment or back pay — is materialised in the payroll documents and declarations.

The corrective payslip#

Issued to make the correction legible and traceable. For an overpayment, it includes a dedicated deduction line (amount, nature). For back pay, it includes the complement rule with corresponding contributions. The 2026 payslip format requires a simplified presentation of contributions — ensure the correction line remains identifiable.

The corrective DSN#

If the relevant month's DSN has already been filed, a corrective DSN adjusts the contribution bases and amounts. Beyond the current month, the correction is reflected in the next DSN with a reference to the period concerned. The monthly payroll cycle and corrective DSN details the technical deadlines and process.

The business acknowledgement (CRM) returned by URSSAF or the pension fund after processing the corrective DSN confirms that the correction has been taken into account. Retain this acknowledgement with the supporting documents.

A 12-employee SME mistakenly pays a €800 bonus in March to an employee whose monthly gross salary is €2,400. The error is detected in April.

Undue amount: €800 gross (the bonus was subject to contributions, so the net overpayment is approximately €600–620, depending on the marginal employee contribution rate).

Step 1 — Written notice: letter or email to the employee in April, explaining the error, the gross and net amounts involved, and proposing a written agreement to recover over 3 months (approximately €200 net per month).

Step 2 — Signed agreement: the employee signs the repayment protocol in April. The employer may now deduct €200 net on each payslip in April, May and June, without being limited by the attachable wage portion.

Step 3 — April, May, June payslips: each payslip includes an identifiable line "overpayment deduction March 2026: -€200.00".

Step 4 — DSN: the April DSN includes a correction of March's contribution base (cancellation of the €800 gross bonus). The May and June DSNs reflect the monthly net deduction without impact on contributions (the base correction was already made in April).

Without the employee's agreement, at a gross salary of €2,400, the monthly attachable wage portion would have been very small, making recovery considerably slower.

An eight-person professional firm discovers during its 2025 year-end review that a former employee who left in November 2024 received an incorrect performance bonus of €1,500 gross in September 2024. The three-year limitation has not elapsed. The employer sends an amicable demand letter to the former employee, citing the legal basis (Article 1302-1 of the Civil Code) and proposing repayment in two instalments. Receiving no response within 30 days, the employer files a claim before the labour tribunal. The evidence file — September payslip showing the incorrect bonus, email documenting the error's discovery, dated demand letter — is straightforward. Well-documented cases of this type are typically settled amicably before the hearing.

1. Attachable wage portion, not a flat 10%: the unilateral deduction limit follows the R3252-2 scale and varies with salary level — verify the current decree.
2. Written agreement: essential to go beyond the attachable wage portion and to secure the procedure.
3. Prior written notice: a deduction without notification is a systematic ground for challenge at the labour tribunal.
4. Legible corrective payslip: a dedicated line, not a deduction buried among other items.
5. Corrective DSN within deadlines: beyond the current month, correct on the next DSN with the reference period.
6. Three-year limitation: act promptly, especially when the employee has left.

In the payroll files we handle, overpayment disputes rarely arise from the law itself — recovery is almost always legitimate. They arise from procedure: a deduction made without explanation, exceeding the attachable wage portion, taken in a single payslip. The winning approach is simple: write before deducting, propose a repayment schedule, respect the legal limit absent an agreement, and document every step.

The distinction between an overpayment and a salary advance also deserves attention: the recovery rules differ, and misclassification can lead to exceeding the applicable legal cap. Where there is any doubt about classification or the applicable attachable wage portion, a payroll coherence review before the correction prevents compounding errors.

Back pay that is genuinely owed must be paid without hesitation — it is a legal obligation. Outsourcing payroll prevents these errors upstream through systematic coherence controls and rigorous variable management.

For complex situations — overpayment spanning multiple months, former employees, impact on pension contributions or the DSN — a review with your accountant before any correction remains the best protection.

Up to date as of 2026-06-14. This article is for information only and does not replace personalised advice. For your situation, contact a chartered accountant registered with the Ordre des experts-comptables.