On 12 March 2026, the Court of Justice of the European Union (CJEU) delivered its judgment in Case C-119/24 (Chefquet), concluding that Belgium’s tax surcharge applied to non-resident taxpayers is incompatible with the EU principle of free movement of workers.
Background
The case originated from a request for a preliminary ruling by the Court of Appeal of Liège, concerning French residents taxed in Belgium on Belgian-source income. The dispute centred on a specific surcharge imposed exclusively on non-resident taxpayers under Belgian income tax law.
The referring court questioned whether this additional charge placed non-residents at a disadvantage compared to resident taxpayers, contrary to Article 45 TFEU.
The Court’s findings
The CJEU held that the Belgian surcharge constitutes a restriction on the free movement of workers.
In particular, the Court found that:
- Applying an additional tax burden solely because a taxpayer is non-resident results in less favourable treatment compared to residents in a comparable situation.
- Such a difference in treatment is liable to deter workers from exercising their right to cross-border employment within the EU.
- The measure could not be justified by the arguments put forward, including the need to preserve the coherence of the tax system or ensure balanced allocation of taxing powers.
Key legal takeaway
The judgment confirms that Member States cannot impose targeted fiscal disadvantages on non-residents unless they are objectively justified and proportionate. In this case, the Court found that Belgium failed to meet that threshold.
Practical implications
National tax regimes: Member States operating differentiated tax surcharges for non-residents may need to amend their legislation.
Cross-border workers: The ruling strengthens protections against discriminatory tax treatment for individuals working across borders.
Employers: Companies with mobile workforces should reassess tax equalisation policies and payroll compliance in light of the decision.
If you need assistance with similar issues regarding labour law, social security, or tax issues, feel free to visit our Global Mobility page for more information and contact us via the dedicated forms.