Soon a reduction of the minimum weekly working hours for part-time workers

From the one-third time rule to the one-tenth time rule?

Currently, except for exceptions, a part-time worker must work at least one third of the weekly working hours of a full-time worker in the same professional category within the company. If you do not employ any full-time staff in the same category, you must use the working hours applicable in your sector as a reference.

From 1 June 2026, this minimum weekly working time will be reduced to one tenth of the full-time weekly working hours.

Concretely, if the full-time working hours in your company are set at:

• 40 hours/week: the minimum weekly working time will be 4 hours
• 38 hours/week : the minimum weekly working time will be 3 hours and 48 minutes

What about the 3-hour rule?

On the other hand, the rule requiring a minimum duration of 3 hours per work performance remains unchanged.

Each work performance must therefore be at least 3 hours. However, there are exceptions to this rule:

• Some categories of workers are exempt from this rule
• Certain sectors have collective agreements allowing deviations from it

Learn more: "What are the legal deviations from the 3-hour rule?"

Do your part-time contracts need to be modified?

Yes, if you want to reduce the weekly working time in your part-time worker's contract, especially to lower it to one-tenth time. In this case, you must first get your worker's agreement and make a contract amendment.

In other words, part-time contracts currently in force in your company will not be changed automatically from 1 June 2026 without your intervention.

Entry into force?

Initially planned for 1 April 2026, these new measures will now apply from 1 June 2026.

What does Securex do for you?

Do you still have questions on this topic? Your Legal Advisor will be happy to help you. Contact them without delay by e-mail at myHR@securex.be.  

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