Author: Evelien Gabriël & Eline Demeyere

On 12 March 2026, the Court of Justice of the European Union ruled that the Belgian additional tax for non-residents, namely the federal surcharges of 7%, is contrary to the free movement of workers within the European Union. This ruling is known as the Chefquet judgment.

What is the Chefquet judgment about?

Non-residents who receive income from a Belgian source, such as salary, pension income or rental income, fall under the non-resident income tax, also referred to as BNI.

Where Belgium is entitled to levy tax under a double taxation treaty, the basic tax is calculated according to the same progressive tax brackets as those applicable to residents.

The difference lies in the additional tax.

·         Belgian tax residents pay an additional municipal tax on top of the basic tax. The rate varies per municipality and ranges between 0% and 9%.

·         Non-residents do not pay a municipal tax, but are subject to federal surcharges of 7% on the basic tax.

Although this system is intended to tax residents and non-residents in a comparable manner, in practice it sometimes leads to a higher tax burden for non-residents. In certain municipalities, residents pay a lower rate than 7%, or even no additional tax at all.

Why is this system contrary to EU law?

According to the Court of Justice of the European Union, this difference constitutes a restriction on the free movement of workers, as laid down in Article 45 of the Treaty on the Functioning of the European Union.

The Court emphasises that it is not required for non-residents to be systematically taxed more heavily. It is sufficient that the Belgian system may, in certain situations, lead to a higher tax burden, for example where a resident lives in a municipality with a low or even no additional tax.

Can you obtain a tax refund?

·         Non-residents who have paid this additional tax may be able to apply for a refund. The following time limits apply.

·         An objection against the tax assessment must be filed within one year after receipt of the tax assessment notice.

The case law of the Court of Justice of the European Union is considered a new fact. As a result, a request for ex officio relief may also be submitted. This is possible up to five years retrospectively, calculated from 1 January of the year in which the tax was assessed.

What does this judgment mean for the future?

The impact of the Chefquet judgment may extend beyond the additional tax for non-residents alone. In Belgium, there has long been debate about municipalities, in particular coastal municipalities, that apply an additional municipal tax of 0%. This issue arises, among other things, in the tax treatment of second residences compared to permanent residents. This inequality has been legally challenged for many years. The judgment may reignite this debate and may place pressure on the broader system of municipal taxation.

How will Belgium respond?

It is currently still unclear how the Belgian legislator will implement this case law. Further adjustments or reforms cannot be ruled out. We are closely monitoring these developments and will be pleased to advise you on the concrete impact on your situation.

Questions about your file or a possible refund? Please contact our experts.