62025CJ0150_RES
Case C‑150/25 [Marhaux] (
i
)
BX
v
État belge
(Request for a preliminary ruling from the tribunal de première instance du Luxembourg (Belgium))
Judgment of the Court (Fifth Chamber) of 12 March 2026
(Reference for a preliminary ruling – Article 45 TFEU – Freedom of movement for workers – Income tax – Employment income received in another Member State – Exemption with progression in the Member State of residence – Failure to apply a bilateral convention for the avoidance of double taxation by a contracting State – Loss of part of the tax advantages relating to the personal and family circumstances of the taxpayer)
Free movement of persons – Workers – Principle of non-discrimination – Posts in the public service – Derogation – Limits – Application solely to measures restricting admission – Taxation of income from an employment in the public service of another Member State falling within the freedom of movement for workers
(Art. 45 TFEU)
(see paragraphs 32-35)
Free movement of persons – Workers – Equal treatment – Income tax – Bilateral tax convention for the avoidance of double taxation – Resident taxpayers in one Member State receiving employment income in a second Member State, taxable in that second Member State and exempt from taxation in the Member State of residence – Tax convention providing for account to be taken of the apportionment of the taxpayer’s personal and family circumstances in proportion to the income taxed in each of the States – Failure by the State of employment to apply the tax convention – Tax legislation of the State of residence resulting in the loss of part of the tax advantages relating to the personal and family circumstances of the taxpayer – Not permissible
(Art. 45 TFEU)
(see paragraphs 47-51, 54, operative part)
Résumé
Ruling on a request for a preliminary ruling from the tribunal de première instance du Luxembourg (Court of First Instance of Luxembourg, Belgium), the Court of Justice states that, in order to ensure the freedom of movement for workers guaranteed by Article 45 TFEU, the State of residence of a taxpayer receiving foreign employment income exempt under a tax convention must take account of all his or her personal and family circumstances, where the State of employment does not apply that convention and does not allow the corresponding tax advantages to be granted in full.
BX is a Belgian tax resident who receives employment income from Belgian and, inter alia, French sources. In accordance with the Belgium-France Tax Convention, (
1
) French-source income is to be taxed in France and is exempt from personal income tax in Belgium. (
2
)
When he submitted his personal income tax returns in Belgium in respect of the 2020 and 2021 tax years, BX deducted from his total income the maintenance payments which he had paid to his daughter and former spouse, who reside in Belgium. The Belgian tax administration, however, granted BX the deduction of the maintenance payments made only in proportion to his Belgian-source income.
Since his initial complaints were unsuccessful, BX brought an action before the referring court, claiming that the rule on the proportionate allocation of the deductible maintenance payments between the Belgian-source income and the foreign-source income, exempt from that tax, is contrary to Article 45 TFEU.
In those circumstances, after finding that the French tax administration misapplied the Belgium-France Tax Convention by not allowing account to be taken of the taxpayer’s family circumstances in proportion to the income taxable in France in respect of the deduction of the part of the non-deductible maintenance payments from that taxpayer’s income taxable in Belgium, the referring court is uncertain whether the Belgian legislation, in so far as it results in the loss in part of the benefit of a tax deduction designed to take account of the personal and family circumstances of resident taxpayers, is compatible with the freedom of movement for workers guaranteed by Article 45 TFEU.
Findings of the Court
The Court recalls that although it is, in principle, for the Member State which applies a principle of taxation, at the place of residence, to the total income of the taxpayers, including that from a foreign source, to take into account in full the personal and family circumstances of those taxpayers, (
3
) such a Member State may, in certain circumstances, be released in part from that obligation, pursuant to conventions for the avoidance of double taxation. (
4
)
However, such a possibility cannot relieve the Member States of their obligation to exercise their powers of taxation in a non-discriminatory way in respect of EU nationals who have exercised their right to freedom of movement for workers, guaranteed in Article 45(1) and (2) TFEU.
Where the Member State of residence concludes a bilateral tax convention by which that Member State and the Member State of employment apportion the taxation of the total income of taxpayers who have exercised their right to freedom of movement for workers and, in proportion to that apportionment, the taking into account of their personal and family circumstances, the Member State of residence must be regarded as having exercised its powers in a non-discriminatory manner only if the taxpayers concerned are guaranteed that, as the end result, all their personal and family circumstances will be duly taken into account, as in the case of resident taxpayers who do not have income from another Member State.
Otherwise, EU nationals who have exercised their right to freedom of movement for workers would be placed in a situation less advantageous from a legal or a factual point of view compared with resident taxpayers who have not exercised their right to freedom of movement for workers, in breach of the principle of non-discrimination, as given concrete expression in particular in Article 45(1) and (2) TFEU.
By contrast, where it appears that the State of employment applies the tax convention in a manner which does not allow taxpayers resident in the Member State of residence to obtain, in the State of employment, a deduction on account of their personal and family circumstances, in proportion to the income received in that State, designed to compensate for the loss suffered in the State of residence, the Member State of residence must be regarded as not being released from its obligation to take account in full of the personal and family circumstances of resident taxpayers.
As a result, the legislation of that Member State of residence, in so far as it does not allow resident taxpayers who have exercised their right to the freedom of movement for workers to regain, in those circumstances, a right to have their personal and family circumstances taken into account in full, must be regarded as imposing a restriction on the freedom of movement for workers, provided that there is no overriding reason in the public interest capable of justifying such a restriction.
(
i
)	The name of the present case is a fictitious name. It does not correspond to the real name of any party to the proceedings.
(
1
)	Convention between France and Belgium seeking to avoid double taxation and to establish mutual administrative and legal rules of assistance in the field of income tax, of 10 March 1964.
(
2
)	French-source income is, however, to be taken into account, after applying a tax scale by income band, in order to determine the tax in Belgium, which is then reduced by the fraction of the tax calculated on the part of the exempt income.
(
3
)	See, to that effect, judgments of 14 February 1995, Schumacker (C‑279/93, EU:C:1995:31, paragraph 32), and of 12 December 2013, Imfeld and Garcet (C‑303/12, EU:C:2013:822, paragraph 43).
(
4
)	See, to that effect, judgments of 12 December 2002, de Groot (C‑385/00, EU:C:2002:750, paragraph 99) and of 15 July 2021, État belge (Loss of tax advantages in Member State of residence) (C‑241/20, EU:C:2021:605, paragraph 44).