Overtime: increase and legal calculation

Introduction: why master the calculation of overtime hours?

Overtime hours are one of the most sensitive issues in French labor law. Every year, thousands of companies face URSSAF adjustments or labor court disputes because they have not correctly applied the rules for bonus rates and counting. In 2026, in a context of tension on the labor market and strengthened labor inspection controls, mastery of the legal calculation of overtime hours is more than ever a priority for any employer. This article presents to you, exhaustively, the legal foundations, calculation methods, applicable bonuses, the annual allowance, as well as the exemption systems in force. HR professionals will also find practical advice to secure their practices through appropriate digital tools, particularly electronic signature for HR which facilitates the formalization of collective agreements and amendments.

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The legal foundations of overtime hours

Legal definition and legal working hours

Under article L. 3121-28 of the Labor Code, all hours worked beyond the legal weekly duration of 35 hours constitute overtime hours. This duration has been fixed since the Aubry II law of January 19, 2000 (law no. 2000-37). The triggering of overtime hours is assessed over the civil week, which runs from Monday 00:00 to Sunday 24:00, unless a company or sectoral agreement defines another reference period.

A distinction must be made between legal duration and maximum legally authorized durations:

• 10 hours per day (article L. 3121-18)

• 48 hours per week (article L. 3121-20)

• 44 hours on average over 12 consecutive weeks (article L. 3121-22)

Any breach of these ceilings exposes the employer to criminal and administrative sanctions.

The annual contingent of overtime hours

Article L. 3121-30 of the Labor Code provides that overtime hours are charged against an annual allowance, set by company agreement or, failing that, by decree. In the absence of a collective agreement, the regulatory allowance is 220 hours per year per employee (decree no. 2004-1381 of December 20, 2004, codified in article D. 3121-24).

Hours completed beyond the annual allowance entitle the employee to a mandatory compensatory rest (COR), equal to:

• 50% of the time worked in overtime hours for companies with 20 or fewer employees;

• 100% of the time for companies with more than 20 employees.

This compensation is distinct from wage increases and is not negotiable downward by collective agreement, except to maintain at least an equivalent level.

Overtime hours and part-time work: not to be confused

Part-time employees cannot work overtime hours in the strict sense: they work complementary hours, within the limit of one-third of the contractual time and without crossing the 35-hour threshold. Beyond 10% of contractual time, each complementary hour is increased by 25%. The rules are therefore different and deserve special attention when drafting contracts — an AI-powered contract generator can prove useful for securing the drafting of these clauses.

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Calculation of overtime hours: method and premium rates

Legal premium rates

Article L. 3121-36 of the Labor Code sets, in the absence of a more favorable collective agreement, the following premium rates:

| Overtime hours | Legal bonus | |---|---| | 1st to 8th hour (H36 to H43) | + 25% | | From the 9th hour (H44 and beyond) | + 50% |

A company or sectoral agreement may modify these rates provided that the minimum rate remains greater than 10% (article L. 3121-36). In practice, many collective agreements provide for higher rates (e.g., construction, chemical industries).

Calculation of the increased hourly rate

The basic hourly rate used to calculate overtime hours is determined according to the following formula:

``` Hourly rate = Gross monthly salary / (Monthly contractual working hours) ```

For a 35-hour/week employee, the monthly duration is 151.67 hours (35 × 52 / 12).

Numerical example: An employee receives a gross monthly salary of €2,500. His basic hourly rate is: 2,500 / 151.67 = €16.48 per hour

If this employee works 4 overtime hours in the week (H36 to H39):

• 25% bonus: 16.48 × 1.25 = €20.60/hour

• Total cost of 4 hours: 4 × 20.60 = €82.40 gross additional

Remuneration or replacement by compensatory rest?

Article L. 3121-33 opens the possibility of replacing all or part of the bonus with replacement compensatory rest (RCR), subject to a collective agreement or, in the absence of an agreement, to the individual agreement of the employee. RCR is often preferred by companies during periods of tight cash flow, but it must be taken within 2 months following the opening of the right.

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Tax and social exemptions on overtime hours

The revised "TEPA" system by the LMPP law

Since the law of August 21, 2007 (the "TEPA" law), remuneration paid for overtime hours benefits from an exemption from income tax. Since 2019, law no. 2018-1213 of December 24, 2018 reintroduced and perpetuated this system, capped at €7,500 per year per employee (article 81 quater of the General Tax Code).

On the social side, overtime hours entitle the employee to a reduction of employee contributions calculated at a fixed rate set by annual order. For 2025-2026, this rate is 11.31% applicable to overtime hour compensation (order of January 28, 2025). On the employer side, a deduction of employer contributions applies to companies with fewer than 20 employees, set at €0.50 per overtime hour completed.

Declaration obligations: DSN and DFS

All overtime hours must be declared monthly via the Nominative Social Declaration (DSN). The standard personnel code (CTP) 066 makes it possible to identify exempted overtime hours. Any omission or coding error exposes the employer to URSSAF adjustment, with application of late payment increases of 5% and late payment interest of 0.2% per month.

Time control obligation: documentary obligation

The judgment of the Court of Justice of the European Union of May 14, 2019 (case C-55/18, CCOO v. Deutsche Bank) reminded employers of the obligation to put in place an objective, reliable and accessible system for measuring daily working time. In France, article L. 3171-4 of the Labor Code requires keeping a record of hours worked beyond 35 hours. This record can take the form of an electronic register, whose evidential value is strengthened when it is signed electronically in accordance with the eIDAS regulation.

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Overtime hours in collective agreements and company agreements

The primacy of company agreements since the Macron ordinances

The ordinances of September 22, 2017 (the "Macron" ordinances) profoundly changed the hierarchy of social standards. Since their entry into force, a company agreement may derogate from the provisions of the sectoral collective agreement on an extended number of topics, including the premium rates for overtime hours (within the limit of a 10% floor) and the annual allowance (article L. 3121-33 of the Labor Code). This increased flexibility requires heightened vigilance: collective agreements must be formalized, retained and enforceable, which argues for their secure electronic signature.

Modulation agreements and annualization of working time

Under a modulation or adjustment agreement for working hours over the year (article L. 3121-44), the qualification of overtime hours is assessed differently: only hours exceeding the annual threshold of 1,607 hours (including the solidarity day) are considered overtime. This mechanism, very widespread in industrial and service sectors, makes it possible to smooth out variations in activity without generating overtime costs for high weeks. Annualization agreements represent documents with high legal value that companies have an interest in formalizing through a company electronic signature solution.

The role of employee representatives

The Social and Economic Committee (CSE) must be informed and consulted when the use of overtime hours exceeds certain thresholds or is part of a structural practice. The consultation report constitutes an opposable document in case of dispute. Its electronic signature, associated with qualified time-stamping, strengthens its evidential value before labor courts.

Legal framework applicable to overtime hours

Foundational texts of French labor law

The overtime hours scheme is mainly governed by the following provisions of the Labor Code:

• Articles L. 3121-27 to L. 3121-48: definition, annual allowance, bonuses, replacement compensatory rest, mandatory rest compensation.

• Articles D. 3121-24: regulatory allowance of 220 hours per year in the absence of a collective agreement.

• Article L. 3171-4: obligation to count hours worked beyond the legal duration.

• Article L. 3121-18 et seq.: maximum daily and weekly durations.

Tax and social provisions

• Article 81 quater of the General Tax Code: exemption from income tax on overtime hour compensation within the limit of €7,500 per year.

• Law no. 2018-1213 of December 24, 2018: perpetuation of the social and tax exemption system.

• Articles L. 241-17 and L. 241-18 of the Social Security Code: reduction of employee contributions and flat-rate deduction for employers.

European and national case law

• CJEU, May 14, 2019, C-55/18 (CCOO / Deutsche Bank SAE): obligation for the employer to put in place a system for monitoring effective, daily, reliable and accessible working time.

• Court of Cassation, Social Chamber: distribution of burden of proof in overtime matters (judgment of March 18, 2020, no. 18-10.919) — the employee must provide elements to support his claim; the employer then provides elements of control of working time.

Evidential value of electronic documents

In litigation relating to overtime hours, electronic documents signed and time-stamped in accordance with the eIDAS Regulation no. 910/2014 (namely articles 25 and 41 relating to qualified electronic signatures and seals) benefit from evidentiary value equivalent to that of a paper document signed in handwriting, in application of article 1366 of the Civil Code. A time-stamped electronic work time register, combined with a qualified signature in accordance with ETSI EN 319 132 (XAdES) or ETSI EN 319 122 (CAdES) standards, constitutes solid evidence before the Labor Court.

Risks in case of non-compliance

Failure to pay or insufficient payment of overtime hours exposes the employer to:

• A wage recovery over 3 years (three-year statute of limitations, article L. 3245-1 of the Labor Code);

• Damages for loss suffered;

• An URSSAF adjustment with late payment increases and interest;

• Criminal penalties in case of exceeding maximum durations (class 4 fine, i.e., €750 per employee concerned, article R. 3124-1).

Usage scenarios: overtime hours and digital tools

Scenario 1 — An industrial SME of 85 employees facing a peak in orders

An industrial company of intermediate size, specializing in the manufacture of electronic components, experiences end-of-quarter peaks in activity requiring between 6 and 9 overtime hours per week and per operator. Before the implementation of a digital tool for managing working time, HR managers manually compiled paper attendance sheets, generating on average 3 to 4 weeks of delay in paying out correct bonuses. Following the adoption of an electronic clocking-in system coupled with HRIS software, with weekly validation via simple electronic signature in accordance with the eIDAS regulation, processing time fell to less than 48 hours. Calculation errors for bonuses were reduced by 78% according to comparable sector benchmarks (source: 2024 ANDRH report on HR digitalization). The estimated annual cost of URSSAF adjustment, estimated at €12,000 on average over the three previous fiscal years, fell to zero after two years of use.

Scenario 2 — An accounting firm managing payroll for 40 SMEs and micro-enterprises

An accounting firm supports about forty clients from micro-enterprises and SMEs whose sectors (catering, construction, retail) involve large volumes of overtime hours. The complexity lies in the multiplicity of applicable collective agreements (IDCC 1979 for catering, IDCC 1597 for construction, etc.) and different bonus rates depending on sectoral agreements. The firm deployed a digital workflow allowing managers to electronically validate hour summaries each Monday morning via an advanced electronic signature. This system, compliant with the requirements of the company electronic signature solution, made it possible to reduce validation exchanges from 5 days to less than 24 hours, and to eliminate disputes related to the subsequent contestation of declared hours. The satisfaction rate of the firm's clients regarding the reliability of payroll increased from 71% to 94% in 18 months.

Scenario 3 — A regional distribution group with 350 employees

A regional distribution network employing approximately 350 full-time and part-time employees wanted to modernize the management of its time modulation agreements. The old processes involved delays in signing amendments of up to 3 weeks, delaying the legal implementation of modulation. After migration to a SaaS electronic signature platform — leveraging the comparison of electronic signature solutions available online to select the solution best suited — contract amendments are now signed in less than 48 hours on average. Time-stamped signature traceability allowed, during a labor inspection check, to instantly demonstrate the compliance of modulation agreements, avoiding a risk of requalification in unpaid overtime hours estimated at around €45,000.

Conclusion

The calculation of overtime hours is both a technical and legal exercise that mobilizes many provisions of the Labor Code, specific collective rules and precise declaration obligations. In 2026, between strengthened labor inspections, European case law on working time monitoring and tax and social exemption systems, employers can no longer afford an approximate management of this item. Digitalization of HR processes — time monitoring, validation of summaries, signature of amendments — is the most effective lever to secure practices and reduce litigation risks. Certyneo supports companies in this approach by offering an eIDAS-compliant electronic signature solution, designed for HR and legal teams. Discover our offers and prices or calculate your return on investment right now.