Belgian social security applicable on RSUs granted by a foreign parent company

The Belgian Supreme Court has held that restricted stock units (RSUs) granted by a foreign parent company to employees of its Belgian affiliate constitute salary subject to Belgian social security contributions, in a ruling dated 29 June 2026 that overturns the Antwerp labour court’s previous position.

Background

In November 2023, the Antwerp Labour Court of Appeal established that RSUs that were granted under a parent company plan with an explicit long-term retention objective (following a selection process in which the Belgian affiliates only suggested candidate names) were neither consideration for work nor a cost borne by the Belgian affiliate and therefore fell outside the scope of social security contributions, relying on the absence of any formal commitment by the Belgian entities and their lack of financial exposure.

The National Social Security Office (NSSO) appealed the ruling.

The Supreme Court's decision

The Supreme Court annulled the Antwerp court’s ruling and grounded its analysis in article 2 of the Wage Protection Act, which defines salary as in-money-valuable benefits to which an employee is entitled by reason of their employment, at the employer’s charge.

The Supreme Court affirmed that benefits granted to retain employees, to encourage continued commitment, and/or to reward conscientious work are by their nature granted as consideration for work performed under an employment agreement and therefore constitute salary. Consequently, where RSUs are granted with a stated retention purpose, this seems to be sufficient to bring them within the concept of consideration for work—irrespective of the formal legal construction of the grant.

Practical considerations

Following this ruling, if Belgian employees are receiving RSUs that are currently treated as exempt from social security, employers may wish to carry out a careful review of their position.