RSUs within international groups: are social security contributions due in Belgium?

What are RSUs?

Restricted Stock Units, or RSUs, are a form of share-based remuneration. Subject to certain conditions, employees are granted the right to receive shares or their corresponding value at a later date.

The actual vesting of RSUs is often subject to certain conditions, such as remaining employed for a specified period. RSUs are therefore frequently used as a tool to retain and motivate employees over the longer term.

When are RSUs considered remuneration for social security purposes?

Belgian social security contributions are due on an employee’s remuneration. Remuneration primarily refers to consideration for work performed.

Benefits that do not constitute direct consideration for work may also fall within the broader concept of remuneration. This is the case where the benefits can be valued in monetary terms and the employee is entitled to them as a result of their employment relationship, at the employer’s expense.

The Court of Cassation had previously clarified that a benefit that does not constitute consideration for work only falls within this broader concept of remuneration if it is at the employer’s expense. This is the case, for example, where the employer has undertaken to grant the benefit to the employee.

Consequently, RSUs granted by a foreign parent company could, in principle, fall outside the concept of remuneration where they:

• did not constitute consideration for work; and

• were not at the expense of the Belgian employer.

The judgment of 29 June 2026 now provides an important clarification regarding the first of these conditions.

New clarification by the Court of Cassation

In the case that gave rise to the judgment, RSUs were granted by a foreign parent company to employees of Belgian subsidiaries. The parent company determined the terms and conditions of the plan, made the final decision on the awards and also bore the financial cost.

The Belgian subsidiaries did, however, play a role in the selection process. They could nominate employees and provide reasons why certain employees should be eligible for an award. In addition, the plan showed that the RSUs were intended, among other things, to retain employees within the company over the longer term.

The Court of Cassation held that benefits granted in order to retain employees within the company, encourage them to continue their efforts or induce them to perform their duties diligently constitute consideration for work. As a result, these benefits qualify as remuneration under employment law.

A retention or motivational purpose can be decisive

The key clarification provided by the judgment is that the retention or motivational purpose of an RSU plan may in itself result in the RSUs being regarded as direct consideration for work.

In that case, it is no longer necessary to determine separately whether the benefit is at the expense of the Belgian employer in order for it to qualify as remuneration.

The fact that a foreign parent company organises the RSU plan, grants the RSUs and bears the financial cost is therefore not necessarily sufficient to exclude Belgian social security contributions.

What does the judgment mean for Belgian employers?

For Belgian employers within international groups, the judgment is particularly relevant where employees participate in an incentive plan that is formally organised by a foreign group company.

Where RSUs are granted to retain employees within the company, motivate them to continue their efforts or encourage them to perform their duties diligently, the Court considers them to constitute consideration for work and, consequently, remuneration.

However, this does not mean that every RSU award made by a foreign company is automatically subject to Belgian social security contributions. A case-by-case analysis remains necessary.

Among other things, the following factors should be taken into account:

• the purpose of the RSU or incentive plan;

• the conditions under which the RSUs are granted;

• any involvement of the Belgian employer;

• the specific circumstances in which employees receive the benefit.

Employers would therefore be well advised to reassess their existing share-based and incentive plans within the group, particularly where Belgian employees participate in those plans.

Our Social Legal experts will be happy to review the structure of your RSU or incentive plan with you and assess the potential impact of the Court of Cassation’s judgment on your company.