Overtime: Salary Increase and Calculation Under Law

Introduction

Overtime is a central issue in French labour law. Whether it is an employee wishing to understand their payslip or an employer seeking to comply with their legal obligations, the calculation of overtime and the applicable increase rates regularly raise complex questions. In 2026, the legal framework derived from the Labour Code (articles L. 3121-28 to L. 3121-40) precisely defines the triggering threshold, minimum increase rates and the modalities of replacement by compensatory rest. This article provides you with a complete and factual guide to master these mechanisms, avoid employment tribunal disputes and optimise the administrative management of your human resources.

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What is overtime?

Legal definition and triggering threshold

Overtime is any hour of work carried out beyond the legal weekly duration of 35 hours set out in article L. 3121-27 of the Labour Code. This threshold is assessed on a civil week basis (Monday 0:00 to Sunday 24:00), unless a collective agreement otherwise provides for organising working time over a multi-week cycle.

For part-time employees, hours worked beyond the contract but below 35 hours per week are complementary hours, subject to a separate regime. They do not fall under the overtime scheme, but nevertheless benefit from a specific increase as soon as they exceed 1/10th of the contractual duration (art. L. 3123-20).

The annual contingent of overtime hours

The statutory contingent of overtime hours is set at 220 hours per year and per employee (art. D. 3121-24), unless a company or sector collective agreement modifies it upwards or downwards. Beyond this contingent:

• The employer must obtain the opinion of the social and economic committee (CSE) before resorting to overtime outside the contingent;

• The employee benefits from a mandatory compensatory rest provision (COR) of 50% for companies with 20 employees or fewer, and 100% for companies with more than 20 employees (art. L. 3121-38).

These thresholds are important to master for employment contract management and their compliant electronic signature, particularly when contract modification addenda need to be established quickly.

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Legal increase rates for overtime

Minimum increase provided by law

The Labour Code provides for minimum increase rates that apply in the absence of a more favourable collective agreement:

| Overtime hour tranches | Minimum increase rate | |---|---| | 1st to 8th overtime hour (H36 to H43) | 25% | | From the 9th overtime hour (H44 and beyond) | 50% |

These rates are calculated on the gross basic hourly remuneration, including salary elements integrated into this base (seniority bonus integrated into the hourly rate, for example). By contrast, exceptional bonuses, expense reimbursements or profit-sharing are generally excluded from the calculation base.

Role of collective agreements

A company or sector agreement may modify these rates downwards to a minimum of 10% (art. L. 3121-33), or increase them beyond 50%. Before proceeding with the calculation, it is therefore essential to verify the applicable collective agreement (IDCC) and any company agreements in force. Collective agreements in the metallurgical sector (IDCC 3127), construction or retail trade frequently provide for specific provisions.

Replacement of the increase by compensatory replacement rest

The employer may, with the employee's agreement or by collective agreement, replace all or part of the salary increase with a compensatory replacement rest (RCR). This mechanism, provided for in article L. 3121-33, is tax-neutral for the employee but allows the employer to lighten the immediate wage bill. The rest must be taken within a maximum period of 12 months.

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How to calculate overtime concretely?

Calculation formula for the increased hourly rate

The calculation is based on the following formula:

Gross hourly rate = Gross monthly base salary ÷ (35 × 52 / 12)

For example, for an employee paid €2,100 gross per month:

• Hourly rate = 2,100 ÷ 151.67 = €13.84 gross/hour

• 25% increase: 13.84 × 1.25 = €17.30 gross/hour

• 50% increase: 13.84 × 1.50 = €20.76 gross/hour

The divisor 151.67 corresponds to the legal monthly duration (35 h × 52 weeks / 12 months).

Practical example: 42-hour week

If an employee works 42 hours in the week (i.e. 7 hours overtime):

• Hours 36 to 43: the first 7 overtime hours are increased by 25%

• Gross additional amount: 7 × 17.30 = €121.10

Tax and social exemption for overtime in 2026

Since the TEPA Act of 2007 and its successive updates, overtime benefits from a favourable exemption regime:

• Exemption from income tax up to a limit of €7,500 per year (limit applicable in 2026, art. 81 quater of the CGI);

• Reduction in employee contributions of 11.31 points on basic and complementary pension contributions (decree no. 2019-797);

• Employer allowance deduction of €1.50 per overtime hour for companies with fewer than 20 employees.

These advantages make overtime particularly attractive for employees, with a net gain often greater than an ordinary taxable bonus. For HR departments, digitising payslips via a compliant solution considerably facilitates the traceability of these variable elements.

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Employer obligations and risks of non-compliance

Keeping the working time register

The employer is legally required to record the effective working time of each employee (art. L. 3171-2 and R. 3243-1). This record may take the form of a badging system, time management software (GTA) or a weekly hourly record signed. This document is evidence in the event of an employment tribunal dispute.

The Court of Cassation recalled in its decision of 18 November 2020 (no. 18-10.919) that in the absence of a reliable recording system, it is for the employer to prove the hours actually worked — not the employee. The stakes are considerable: the burden of proof is reversed.

Penalties for non-payment

Non-payment of overtime exposes the employer to several risks:

• Back pay with legal interest before the Employment Tribunal;

• Damages for disloyal performance of the employment contract;

• Unlawful work if the default is intentional (art. L. 8221-5), liable to a fine of €45,000 and 3 years' imprisonment for natural persons;

• URSSAF adjustment with application of late payment increases.

To secure these processes and produce irrefutable evidence in the event of a dispute, many HR departments now rely on qualified electronic signature compliant with eIDAS to validate hours records and contract addenda.

Absolute maximum working hours to be observed

Even in the presence of overtime, the employer cannot exceed the absolute legal ceilings:

• 10 hours per day (except for prefectoral derogation or collective agreement);

• 48 hours per week (absolute maximum duration, art. L. 3121-20);

• 44 hours on average over any period of 12 consecutive weeks (art. L. 3121-22).

These limits apply even when a collective agreement organises the annualisation of working time. Vigilance is particularly important in sectors with high seasonality (tourism, construction, logistics).

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Administrative management and digitisation of documents relating to overtime

Contract addenda and formal requirements

Certain changes to working time (transfer to a day-rate convention, annual modulation, recurring recourse to overtime beyond the contingent) require an addendum to the employment contract, which must be signed by both parties to be enforceable. Article 1366 of the Civil Code fully recognises the legal value of electronic signature, provided that it guarantees the identity of the signatory and the integrity of the document.

Electronic signature for human resources precisely addresses this need: remote signature of addenda, qualified timestamping, preservation of signature evidence for the entire statutory limitation period (5 years in salary matters).

Digitised payslips and traceability of variable elements

Since the decree of 16 December 2016, the employer may provide the payslip in electronic form without prior agreement from the employee (art. L. 3243-2), provided it guarantees its integrity and accessibility. Overtime, its number and its increase rate must be shown distinctly (art. R. 3243-1, 15°).

The use of an electronic signature solution integrated into the HRIS enables the centralisation of validation of hours records, payslips and addenda in a single environment, auditable at any time by the labour inspectorate or in the event of employment tribunal proceedings.

Legal framework applicable to overtime

Reference texts of the Labour Code

The overtime regime is governed by articles L. 3121-27 to L. 3121-40 and D. 3121-24 of the Labour Code, arising from the Labour Act of 8 August 2016 (Act no. 2016-1088) and its implementing orders. These provisions distinguish:

• Rules of absolute public policy (maximum durations, minimum threshold of 10% in the event of a derogatory agreement);

• Suppletive rules applicable in the absence of a collective agreement (increase rates of 25% and 50%, contingent of 220 hours);

• The scope open to collective bargaining.

Tax regime: article 81 quater of the CGI

The exemption from income tax on overtime is codified in article 81 quater of the General Tax Code, amended by the Finance Act for 2019 (Act no. 2018-1317). The exemption ceiling is €7,500 per year in 2026. This provision applies only to hours legally qualified as overtime (beyond 35 hours per week or the conventional ceiling).

Social contribution reductions

The reduction in employee contributions is defined by article L. 241-17 of the Social Security Code and clarified by decree no. 2019-797 of 26 July 2019. The current reduction rate is 11.31 points for employees under the general scheme. The employer allowance deduction of €1.50 per hour is reserved for companies with fewer than 20 employees (art. L. 241-18 CSS).

Legal value of electronic signature on HR documents

Addenda relating to working time arrangements are legal acts within the meaning of article 1366 of the Civil Code, which recognises that "electronic writing has the same probative force as writing on paper". Article 1367 of the Civil Code clarifies that electronic signature is reliable as soon as it makes it possible to identify the signatory and guarantees the integrity of the document.

The eIDAS Regulation no. 910/2014 of the European Parliament and of the Council of 23 July 2014 establishes three levels of electronic signature:

• Simple: for low-stakes documents;

• Advanced: for ordinary contracts and addenda;

• Qualified: the only level legally equivalent to handwritten signature throughout the EU.

For overtime hours records and modulation addenda, advanced or qualified electronic signature is recommended to guarantee their enforceability in the event of a dispute. The ETSI EN 319 132 standard defines the XAdES/PAdES formats accepted for long-term validation (LTV) signatures with probative value.

Risks in relation to unlawful work

Article L. 8221-5 of the Labour Code qualifies as unlawful work the intentional statement on the payslip of a number of hours lower than that actually worked. The criminal penalties reach 3 years' imprisonment and €45,000 fine for natural persons, increased to €225,000 for legal persons (art. L. 8224-1 and L. 8224-5). The case law of the Court of Cassation also condemns the systematic recourse to unpaid overtime as an ordinary mode of management.

Usage scenarios: managing overtime with electronic signature

Scenario 1 — Industrial SME with high seasonality

An SME in the mechanical manufacturing sector, with about 80 employees, experiences recurring peaks of activity from April to September. Each year, its production teams work on average 15 to 18 hours overtime per employee during high-load weeks, necessitating the drafting of several dozen annual modulation addenda and weekly hours records countersigned.

Before digitisation, the process involved printing, handwritten signature, digitisation and physical archiving — approximately 45 minutes per file for the HR department. By deploying an advanced electronic signature solution compliant with eIDAS for these documents, the company reduced this time to less than 8 minutes per file, i.e. a reduction of 82% of administrative processing time. The addenda are signed remotely by operators from their mobile phone, and traceability is automatically preserved for the entire statutory limitation period.

Scenario 2 — Accounting firm managing payroll for 150 micro and small/medium enterprises

An accounting firm specialising in payroll management ensures remuneration follow-up for approximately 150 client companies, representing 2,000 monthly payslips including variable elements (overtime, bonuses, COR). Each month, a significant proportion of these payslips require the validation of a hours record by the employer before payroll processing.

Thanks to the integration of an electronic signature workflow, heads of client companies validate their hours records online in less than 2 minutes, compared to 24 to 48 hours previously via email or postal exchanges. The firm estimated a gain of 3 person-days per month on follow-up and collection of validations, enabling the reallocation of these resources to higher value-added tasks.

Scenario 3 — Distribution group with multi-site employees

A food distribution group operating about twenty outlets in the region employs approximately 400 employees, the majority of whom work part-time with variable complementary and overtime hours each week. The HR department must manage in real time the breaches of contingent, requests for compensatory rest and occasional addenda for last-minute replacements.

By connecting its GTA software to an electronic signature API, the group automates the generation and signature of weekly addenda as soon as a triggering threshold is reached. The signature period has fallen from 5 working days to less than 4 hours on average. This responsiveness made it possible to reduce by 65% the employment tribunal disputes related to unsigned or late-signed addenda, according to the internal analysis by the legal department over 18 months.

Conclusion

Overtime is subject to a precise legal framework that every employer must master: triggering threshold at 35 hours, increase rates of 25% then 50%, annual contingent of 220 hours, tax and social exemptions capped at €7,500 per year. Non-compliance with these rules exposes employers to significant employment tribunal and criminal risks, whilst good management of these variable elements strengthens team confidence and payroll reliability.

The digitisation of associated documents — addenda, hours records, payslips — is today an essential lever for HR efficiency. Certyneo offers you an electronic signature solution compliant with eIDAS, specifically tailored to the needs of HR and legal teams.

Ready to secure and accelerate your document processes? Discover our pricing and get started free on Certyneo today.