Is it possible to file a joint tax return in Luxembourg if one partner works for a European institution?

If the partner has come to Luxembourg solely to work in a European institution: their tax residence remains in their country of origin, even if the couple lives in Luxembourg.

• For married couples, joint taxation remains possible by ticking Article 3(d) of the Income Tax Law, provided that at least 90% of the household's professional income is earned during the tax year by the taxpayer resident in Luxembourg.

• For civil partners, joint taxation is not possible in this case.

If the partner was already living in Luxembourg or arrived for a reason other than employment with the European institution, their tax residence is, in principle, Luxembourg. Joint taxation is then possible, according to the standard rules for marriage or civil partnership (the latter must have existed for the whole year and the partners must have lived together).

Updated on: 21/01/2026