As from 1 April 2026 Belgian workers may perform up to 360 hours of voluntary overtime per year.
1. General principles and quantitative limits
The new regime provides for an annual quota of 360 voluntary overtime hours per employee. These hours may be performed without any specific justification and do not entitle the employee to compensatory rest. The system is designed to allow employees to voluntarily increase their remuneration by performing overtime with the employer’s consent.
Out of these 360 annual voluntary overtime hours:
- 240 hours are exempt from professional withholding tax, personal income tax and social security contributions. These hours are paid without any overtime premium, and no surcharge may be granted.
- The remaining 120 hours are fully subject to social security contributions and taxation. An overtime premium becomes payable as soon as these hours exceed either the daily limit of 9 hours or the normal weekly working time applicable within the undertaking.
Voluntary overtime hours are not taken into account for the internal working time limits. However, the European working time limit remains applicable: total working time (including overtime) may not exceed 48 hours per week on average over a reference period of four months.
The regime applies across all industries.
In the hospitality (horeca) industry, the existing quota is increased to 450 voluntary overtime hours per year for employers operating with a certified cash register system[1].
2. Obligation to conclude a prior written agreement
Voluntary overtime may only be performed if the employee agrees thereto, and the employer authorises the performance of such hours.
A prior written agreement should be concluded between the employer and the employee. Such agreement constitutes a mere declaration of intent and is valid for one year, with the tacit annual renewal.
The agreement may be general in scope, or more specific or occasional. The parties enjoy contractual freedom in this respect.
The agreement may be terminated unilaterally at any time by either party, in writing, subject to a one-month notice period, or terminated at any time by mutual consent.
Importantly, the employer may not force an employee to enter into such an agreement, nor subject the employee to any disadvantageous treatment as a result of a refusal to do so.
The draft legislation also governs the treatment of existing voluntary overtime agreements. Any agreement entered into by an employee prior to 1 April 2026 to perform voluntary overtime for a period extending beyond that date will remain valid and will be deemed to constitute an agreement under the new regime, until the expiry of its original term. Upon expiration, the parties will have to conclude a new agreement in accordance with the new rules.
3. No additional formalities or justification required
As a reminder, voluntary overtime hours are not subject to additional formalities or specific procedures and do not need to be justified by an extraordinary workload or unforeseeable event (except for part-time employees – see the specific conditions below, section 4). No statutory derogation needs to be invoked. The sole requirement is the existence of a valid prior written agreement between the employer and the employee.
4. Employees concerned
Under the new regime, part-time employees are only allowed to perform voluntary overtime in the event of a temporary increase in workload, and provided they have been employed under a part-time employment contract with the same employer for at least three years.
The new regime also expressly provides that employees working part-time due to a reduction of working time in the context of career breaks, time credit or thematic leave (such as parental leave) may not perform any voluntary overtime. While this prohibition already existed in practice, it was not explicitly set out in the legal provisions.
A transitional period nevertheless applies: the restriction for part-time employees will not apply to part-time workers who, on the date of publication of the new legislation, are already bound by a voluntary overtime agreement with their employer, provided they were already performing voluntary overtime as part-time employees with that same employer.
5. Key takeaways for employers
The new regime provides for an annual quota of 360 voluntary overtime hours per employee, which may be performed without any specific justification and without entitlement to compensatory rest. Of these hours, 240 benefit from a favourable social security and tax treatment, as they are paid without any overtime premium and are exempt from social security contributions and taxation.
No specific formalities or procedures are required, subject to the conclusion of a prior written agreement between the employer and the employee. Such agreement is valid for one year, may be tacitly renewed, and may be drafted in general or specific terms, depending on the parties’ needs.
[1] Of these 450 hours:
– 360 hours remain exempt from social security contributions, personal income tax and professional withholding tax and are paid without overtime premium;
– the remaining 90 hours are paid with an overtime premium and are fully subject to social security and tax charges.
If you have any questions regarding the topics discussed in this article, please feel free to contact the authors of this article, Alexis Ceuterick or Marie-Ysaline Lannoye.
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This newsletter does not constitute legal advice or a legal opinion. Please consult with a legal counsel of your choice before taking any action based on the information provided.