How to implement it?

The Labour Deal states that the work rules may allow full-time employees to spread their 38 hours of work over four days, with 9.5 hours per day. However, if they are employed between more than 38 hours and a maximum of 40 hours per week, only a company CBA may allow full-time employees to spread their hours over four days at a rate of 10 hours per day.  

It is therefore up to the employer to decide whether the four-day work week system should be implemented within the company.

In case the employer intends to introduce this system, he should :

  • amend the work regulations following the usual legal procedure when the actual weekly working time is equal to 38 hours maximum; or
  • conclude a company CBA when the actual weekly working time exceeds 38 hours and does not exceed 40 hours.

The Labour Deal does not stipulate anything in the case the employer does not intend to introduce the four-day work week system. There is therefore no legal obligation for the employer to motivate his refusal in such a case.

Individual employee’s request

Once the employer has decided to implement the four-day work week system, the employees have the possibility to submit a written request (e.g. by e-mail), only valid for a renewable period of up to 6 months.

If the employer agrees to the request, a written agreement must then be concluded at the latest when the employee begins to work in such system. This agreement must specify:

  • the beginning and end of the working day;
  • the time and duration of rest intervals and regular work stoppage which are applied during the four-day work week;
  • the start and end dates of the period during which the four-day work week is applied without exceeding the maximum period of 6 months.

A new agreement must be concluded if the 6-month period is extended.

The employer has no obligation to accept this request. In such case, the employer must motivate the refusal in writing (e.g. by e-mail) and communicate it to the employee within one month. The Labour Deal does not comment on the valid reasons that could justify this refusal nor does it sanction absent motivation. However, we are of the opinion that this refusal should remain objective, such as for organisational reasons.

Protection against dismissal

The Labour Deal provides that employees who apply to enter the four-day work week benefit from protection against dismissal based on their choice in favour of this system. However, such protection is not absolute. An employer still has the right to terminate the employment contract for reasons unrelated to this request. Furthermore, the employer must ensure that these employees are not treated adversely.

The mechanism of protection against adverse treatment is not developed by the Labour Deal. We are thus of the opinion that in case of adverse treatments, the employees will have to invoke the already existing protection mechanisms (e.g. manifestly unreasonable dismissal), which are not specifically linked to the four-day work week.

Additional administrative formalities

Both the employee's request and the agreement (or a copy thereof) must be kept, for the period to which they relate, in the place where the work rules can be consulted. Thereafter, the employer must retain them for a period of 5 years. Furthermore, the health & safety committee (or, in its absence, the trade union delegation) and the employee must be provided with a copy of this agreement.

If the employer does not does not comply with these obligations or is unable to provide the documents to the labour inspectorate in the event of an inspection, he is liable to a level 2 fine (i.e. a criminal fine of between EUR 400 and EUR 4.000 or an administrative fine of between EUR 200 and EUR 2.000), multiplied by the number of employees concerned.


Employees who decided to enter the four-day work week system are no longer allowed to perform overtime.


This four-day work week system is not a reduction in working hours, as the employees will have to perform longer days in order to carry out the weekly working hours applicable in the company on four days instead of five. This system aims to allow them to adapt their working hours to their private life.

Despite the fact that this system has been implemented for the benefit of the employees, the employer's choice remains, in practice, decisive. Furthermore, in view of the considerable administrative burden and the criminal sanctions attached to it, as well as the still vague protection mechanisms granted to the employees, employers may be reluctant to introduce such system.

If you have any questions on the above, do not hesitate to contact one of our colleagues in the Employments & Benefits team, we will be please to assist you.

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