Overtime Hours: Increase and Legal Calculation

Introduction

Overtime hours constitute one of the most closely scrutinised employment law topics by both employers and employees. Between calculating the applicable increase rate, respecting the annual contingent and the tax and social exemptions provided for by law, the matter is both technical and evolving. A calculation error exposes the company to wage recovery claims, late payment increases and, where applicable, to labour court proceedings. This article guides you step by step through the legal rules in force, concrete calculation mechanisms, and good practices in working time management — including digital tools that secure the traceability of agreements.

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Legal definition of overtime hours

What is an overtime hour?

In accordance with article L. 3121-28 of the French Labour Code, all hours of work performed beyond the legal weekly duration set at 35 hours constitute overtime hours. This threshold is assessed on the basis of the calendar week (Monday 0 h to Sunday 24 h), unless working time has been adjusted by collective agreement.

For employees whose working time is organised over a period greater than a week (modulation, annualisation), overtime hours are counted differently: they correspond to hours exceeding the annual ceiling of 1,607 hours (or the lower collective ceiling that may be applicable).

Who is affected?

Only employees subject to the legal duration of work are affected. Those excluded from the scheme are:

• Senior executives (article L. 3111-2 of the French Labour Code), who are not subject to the working time regulations.

• Employees on day-based contracts, for whom the concept of overtime hours does not apply in the same way (mechanisms for exceeding days exist, however).

• Self-employed workers and sole traders.

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Applicable increase rates

The legal scale: 25% and 50%

The French Labour Code (article L. 3121-36) sets the following minimum increase rates:

| Overtime hours | Legal increase rate | |---|---| | 1st to 8th hour (H36 to H43) | + 25% | | Beyond the 8th hour (H44 and beyond) | + 50% |

These rates apply to the basic hourly wage, excluding bonuses and benefits in kind, unless a more favourable collective provision applies.

Collective agreements may modify these rates

A company or industry agreement may lower the increase rate to a minimum of 10% (article L. 3121-33 of the French Labour Code), which constitutes the absolute floor below which no exemption is possible. Conversely, nothing prevents providing for rates higher than 25% or 50% for the first tranches.

It is therefore essential to consult the collective agreement applicable to your sector before any calculation. Companies without a collective agreement remain subject to the legal scale by default.

Replacement of the increase by compensatory rest

Article L. 3121-33 of the French Labour Code permits replacement of all or part of the salary increase by replacement compensatory rest (RCR). This rest must be equivalent in value to the increase due. For example, one overtime hour increased by 25% entitles to 1 h 15 min of rest. This mechanism is widely used to limit the impact on the payroll whilst rewarding the employee's commitment.

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Concrete calculation of overtime hours

Basic formula

The calculation of overtime pay follows the following formula:

Overtime Pay = Basic hourly wage × (1 + increase rate)

Practical example:

• Monthly gross salary: €2,500

• Monthly reference duration: 151.67 hours (35 h × 52 / 12)

• Basic hourly wage: 2,500 / 151.67 = €16.48/h

• 5 overtime hours at 25%: 5 × 16.48 × 1.25 = €103

• 3 overtime hours at 50%: 3 × 16.48 × 1.50 = €74.16

The annual overtime contingent

Article L. 3121-30 of the French Labour Code sets the legal contingent at 220 hours per year and per employee. A collective agreement may set a different contingent (higher or lower). Beyond the contingent, overtime hours remain possible but entitle to a mandatory compensatory rest entitlement (COR), the rate of which is:

• 50% in companies with 20 employees or fewer;

• 100% in companies with more than 20 employees.

Exceeding the contingent also requires prior notification to the Works Council (CSE — Comité Social et Économique).

Tax and social exemptions: the "TEPA Law" scheme

Since the law of 21 August 2007 (known as the TEPA law), strengthened by the "Purchasing power" law of 2022, remuneration relating to overtime hours benefits from:

• Income tax exemption up to €7,500 per year (article 81 quater of the French Tax Code).

• Reduction in employee social security contributions on remuneration paid for overtime hours.

• Forfeit deduction of employer contributions for companies with fewer than 20 employees.

These tax and social benefits make overtime hours a lever for optimising net remuneration, but they require rigorous traceability of hours actually worked.

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Traceability, compliance and digital tools

The obligation to record working time

The employer is legally required (article D. 3171-8 of the French Labour Code) to keep a record of the duration of work of each employee, hour by hour, day by day. This document must be kept for one year and made available to the labour inspector and the Works Council on request.

In the event of URSSAF inspection or labour inspection, the absence of precise recording can result in a reclassification of the duration of work and contribution recovery, together with increases that may reach 10% to 40% of the amount evaded.

Formalisation of agreements: the role of electronic signature

When an agreement on overtime hours — or an individual amendment — must be concluded, the question of signature arises acutely. Using electronic signature for HR contracts makes it possible to guarantee time-stamping, document integrity and certain identification of the signatory, three essential elements in the event of labour litigation.

In this context, it is useful to understand the levels of electronic signature provided for by eIDAS regulation: a simple electronic signature is sufficient for most HR amendments, whilst an advanced or qualified signature will be recommended for collective agreements with significant financial implications.

For SMEs seeking to structure their documentary process without heavy infrastructure, the comprehensive guide to electronic signature in business provides an overview of solutions suited to each organisation size.

Archiving and retention period

Payslips, time records and agreements relating to overtime hours must be retained for 5 years (limitation period for salary matters, article L. 3245-1 of the French Labour Code). In the event of a dispute, the burden of proof rests with the employer to demonstrate that the hours claimed were not worked — or that they were properly paid.

A system of electronic signature and compliant archiving provides a probative audit trail, difficult to challenge before the judge. It also reduces the processing time for work time adjustment agreements, often synonymous with administrative bottlenecks in multi-site companies.

Finally, to assess the return on investment of such a digitalisation process, HR teams can use the electronic signature ROI calculator available on Certyneo.

Legal framework applicable to overtime hours

French overtime regulation is based on a dense legal corpus, articulated between the Labour Code, collective agreements and several emergency laws.

Labour Code — reference texts:

• Article L. 3121-28: definition of overtime hours beyond the 35-hour legal duration.

• Article L. 3121-30: legal annual contingent set at 220 hours per employee.

• Article L. 3121-33: possibility of exemption by company or industry agreement, with a minimum increase of 10%.

• Article L. 3121-36: legal increase rates (25% then 50%).

• Article L. 3121-37: mandatory compensatory rest beyond the contingent.

• Article D. 3171-8: obligation to record daily and weekly work duration.

• Article L. 3245-1: five-year limitation period for salary matters.

Tax provisions:

• Article 81 quater of the French Tax Code: income tax exemption up to €7,500 annually for overtime hours.

• Law No. 2007-1223 of 21 August 2007 (TEPA law) and its developments from the Law No. 2022-1158 of 16 August 2022 (purchasing power): reduction in employee contributions and forfeit employer deduction.

Key case law:

• The Social Chamber of the Court of Cassation regularly reminds (notably Cass. Soc., 18 March 2020, No.18-10919) that if the employee produces sufficiently precise information on the number of hours claimed, it is for the employer to contradict this information by providing evidence of actual working time. The absence of a record therefore constitutes a major litigation risk.

Risks of non-compliance:

• Recovery of wages + legal interest over 5 years in case of unpaid hours.

• URSSAF redressment with increases (10% to 40%) if exemptions have been wrongly applied.

• Offence of concealed work (article L. 8221-5 of the Labour Code) if overtime hours are deliberately hidden, punishable by a fine of €45,000 and 3 years' imprisonment for the natural person.

• Liability of the employer in case of exceeding maximum working hours (10 h/day, 48 h/week, 44 h on average over 12 weeks).

Documented and time-stamped management — in particular via electronic signature tools compliant with eIDAS regulation No. 910/2014 — constitutes the best probative protection against these risks.

Use cases: managing overtime in the business

Scenario 1 — An industrial SME of 45 employees during high activity period

An industrial SME specialising in automotive subcontracting must cope with a spike in orders over two months. The employer asks 20 production employees to perform between 6 and 8 overtime hours per week for 8 weeks, a total of 48 to 64 overtime hours per employee.

Before launching the campaign, the HR manager checks the residual contingent for each employee (legal contingent of 220 h/year) and finds that some employees have already worked 90 hours since January. He formalises individual amendments to the organisation of working time via an electronic signature platform, which allows him to collect approvals in less than 24 hours compared to 3 to 4 days previously in paper format. Automated time recording makes it possible to calculate with precision the increases at 25% (H36-H43) and 50% (H44+), and to integrate the amounts into the following month's payroll. Result: zero payroll errors on the campaign, processing time reduced by 70%.

Scenario 2 — An accounting firm of 18 staff during the fiscal period

During the financial close period (March-April), an accounting firm mobilises its staff beyond the 35 weekly hours. Rather than pay an increase in cash — which would weigh on the firm's cash flow — the manager opts for replacement compensatory rest (RCR), provided for in the company agreement.

Each overtime hour increased by 25% automatically generates 1 h 15 of rest credited to an individual counter accessible online by each employee. The formalisation of the company agreement on RCR, co-signed electronically by the staff representative and the manager, is archived with qualified time-stamping. In the event of labour inspector inspection, the firm has a complete audit trail, accessible in a matter of seconds. This organisation has made it possible to reduce tensions relating to uncompensated hours and improve team satisfaction by 15 points on the annual internal survey.

Scenario 3 — A group of private clinics managing complex schedules

A group of private clinics with around 600 beds must manage schedules for healthcare workers subject to annual working time cycles. Overtime hours are only counted at the end of the cycle, which complicates HR monitoring. A modulation agreement has been negotiated with union delegates, providing for a trigger threshold for overtime hours at 1,607 hours annually.

Thanks to a time management tool coupled with an electronic signature solution, amended scheduling amendments (cycle changes, make-up of unused leave) are signed on mobile by health managers. This process has reduced approval times from 5 days to less than 4 hours, and has made it possible to automatically detect contingent overruns before they generate unforeseen rest obligations. The payroll department recorded a 30% reduction in payroll anomalies related to overtime over the last 12 months.

Conclusion

The calculation of overtime hours and the application of legal increases do not tolerate any approximation: rates of 25% or 50%, a contingent of 220 hours, tax exemptions conditional on irreproachable traceability — each parameter has a direct impact on payroll and company compliance. Beyond mastering legal rules, it is the quality of time recording, formalisation and archiving tools that makes the difference in the event of inspection or litigation.

Digitalising the management of amendments, company agreements and time records with an eIDAS-compliant electronic signature solution transforms an administrative constraint into an operational advantage. Certyneo supports HR teams in this approach with simple, secure and auditable workflows.

👉 Discover our HR solutions on Certyneo and secure your working time agreements management from today.