Finding your tax office in Luxembourg

Key figures

Tax office or RTS office: who does what?

The ACD separates two roles (ACD organizational chart (ouvre dans un nouvel onglet)).

• The tax office determines your final tax based on your tax return (model 100), calculates your tax advances, and issues residence or income certificates.
• The RTS office manages tax withholding on wages and salaries: it issues and amends your tax card (model 164 R for residents, 164 NR for non-residents) and calculates your annual adjustment (model 163). The six offices are RTS 1, RTS 2, RTS 3, RTS Esch-sur-Alzette, RTS Ettelbruck, and RTS Non-residents (ACD list (ouvre dans un nouvel onglet)).

For a resident, the RTS office also depends on the municipality. A tax card correction therefore does not go to the same place as a tax return. Details on the tax card can be found on our tax card page.

Cross-border workers: Luxembourg X, Y, Z and RTS Non-residents

The four departments share the same address: 21, rue Eugène Ruppert, L-2453 Luxembourg (Yris building), postal address B.P. 1706, L-1017 Luxembourg (ACD (ouvre dans un nouvel onglet)).

If you apply for tax assimilation, your tax return also goes to X, Y, or Z.

When profession changes the tax office

The ACD distributes its 28 tax offices for individuals (not all of its services) "based on the taxpayer's municipality of residence or profession". Two examples from its pages: the Diekirch office (ouvre dans un nouvel onglet) also handles resident lawyers registered with the Diekirch bar, and Luxembourg 1 (ouvre dans un nouvel onglet) handles the diplomatic corps. If you are self-employed or have a special status, check your office's competence sheet before sending your return.

A concrete example

Let's take Inès, an employee in Luxembourg, who lives in Arlon until June 2025 and then moves to Esch-sur-Alzette.

1. From January to June, her tax card falls under the RTS Non-residents office; changes are requested using model 164 NR.
2. Once resident, her tax card transfers to the RTS office responsible for Esch-sur-Alzette, according to the ACD table.
3. Having settled in Esch-sur-Alzette, her tax office becomes Esch-sur-Alzette 1. For the year of the move, the ACD helpline confirms where she should submit her 2025 tax return (model 100), before 31 December 2026.
4. If she wants to be taxed as a resident for the entire year 2025, she ticks box 401 on model 100 and provides proof of her annual income.

To find out if this filing is mandatory or if an annual adjustment is enough, our tax return or annual adjustment guide lays it out.