No tax card in Luxembourg: why 33% is withheld
If your first Luxembourg payslips show a flat 33% income tax and no tax class, your employer has not received your tax card (fiche de retenue d'impôt). It is a legal default, not a mistake, and the excess comes back.
What the law says
When an employer has no tax card for an employee, it must withhold income tax at the class 1 rate without any reduction, which works out to a flat 33% of the taxable salary. The payslip usually shows 'retenue d'impôt 33%' or 'classe --' and no tax credits (CIS, CI-CO2) because those are only applied on the basis of a card.
Why you have no card
Residents receive their card automatically from the ACD (Administration des contributions directes) after registering with the commune; new arrivals often wait a few weeks. Non-residents (cross-border workers) must request it once with form 164 NR, with a copy of the employment contract. A change of employer, of address or of family status also triggers a new card.
How to fix it
Contact the ACD office in charge of your file (RTS non-résidents for cross-border workers) and ask for the card; give the copy to your employer as soon as you have it. Payroll then applies your real tax class from the next payslip. Many employers also regularise the previous months in the same year, but they are not obliged to.
Getting the excess back
Anything withheld above your real tax for the year is recovered through the annual adjustment (décompte annuel, form 163) or a full return (form 100). The deadline is 31 December of the following year. If you earned in Luxembourg for only part of the year, the refund is often several hundred euros per month of 33% withholding.
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Questions people ask
Is 33% also applied to the 13th month?
Yes, without a card every taxable payment is withheld at 33%, including bonuses and the 13th month.
I am married; which class will I get?
Non-residents default to class 1. Married cross-border workers can request assimilation (class 2) if at least 90% of household income, 50% for Belgian residents, is taxable in Luxembourg.
Related guides
- Your first Luxembourg payslip, explained line by line
- Tax class 1, 1a or 2: which one applies to you
- Cross-border telework: the 34-day rule
Indicative rules as of October 2026. Not tax or legal advice.