In general, non-resident taxpayers who receive income that is taxable in Luxembourg may be subject to tax obligations in Luxembourg.
Certain non-resident taxpayers are required to file an income tax return (known as taxation by assessment).
Other taxpayers can regularise their tax situation by filing a tax return or by applying for an annual adjustment.
All taxpayers are required to declare their income if the Luxembourg Inland Revenue ("Administration des contributions directes" - ACD) requests them to do so.
Who is concerned
Any taxpayer can:
- be ordered to declare their income; or
- decide on their own to file a tax return; or
- request an annual adjustment.
As long as non-resident taxpayers carry out their profession in Luxembourg and keep their domicile abroad, they remain a fiscal non-resident in Luxembourg and a fiscal resident in the country in which they have their domicile. In this case they are not treated as Luxembourg fiscal residents.
The income tax return (form 100) should be filed with the relevant tax office preferably by 31 March of the year following the tax year concerned, and observing the specific submission deadlines indicated by the different departments of the Luxembourg Inland Revenue (Administration des contributions directes - ACD).
Taxpayers who can file a tax return or apply for an annual adjustment of their withholding tax on salaries or pensions for the year N have to do it by 31 December of the year N+1 at the latest.
How to proceed
Taxpayers required to file an income tax return
The taxpayer must submit an income tax return (via form 100) if he has been employed as a salaried worker in Luxembourg for at least 9 continuous months during the tax year, and:
- the annual taxable income at source in Luxembourg exceeds EUR 100,000;or
- if, in case of multiple income streams of non-exempt remunerations, the annual income exceeds EUR 36,000 for tax class 1 or EUR 30,000 for tax class 1A.
Example: a taxpayer has several salaried activities with several employers at the same time.
The taxpayer must also submit an income tax return (via form 100), if:
- their annual income resulting from a pension, taxable at source in Luxembourg, exceeds EUR 100,000;or
- their taxable income in Luxembourg is not subject to tax withholdings at source, such as:
- earnings from self-employment;
- income from the rental of property located in Luxembourg;
- wages or salaries paid by a foreign employer, or pensions paid by a foreign pension fund; or
- his taxable income includes net investment income, such as dividends, and the debtor is:
- the State of Luxembourg; or
- a commune; or
- a Luxembourg public-sector establishment; or
- a company under private law whose registered office or central administration is in Luxembourg; or
- a natural person who has their fiscal domicile in Luxembourg; or
- their income from Luxembourg sources consists of directors' fees of a gross annual amount exceeding EUR 100,000;or
- spouses who are not separated, one of whom is a resident taxpayer and the other a non-resident, who chose to be jointly taxed and who provisionally obtained tax class 2 on their tax card.
The non-resident taxpayer is also required to declare their income if the Luxembourg Inland Revenue ("Administration des contributions directes" - ACD) so requests.
Taxpayers for whom the filing of an income tax return is optional
Taxpayers can file an income tax return (via form 100) in one of the following cases:
- they opt for a tax treatment equivalent to that of a resident taxpayer to be entitled to the same deductions, allowances and tax credits as resident taxpayers (details to be found on the corresponding information page);
- they request to be taxed jointly with their spouse in order to qualify for the class 2 tax rate;
- they have requested to be taxed jointly with their partner in order to qualify for the class 2 tax rate. The 3 neighboring countries of Luxembourg all recognise formal civil partnerships, namely the "Civil Solidarity Pact" in France, the "Legal Cohabitation Contract" in Belgium and the "Eingetragene Lebenspartnerschaft" in Germany;
- they received directors' fees from Luxembourg sources in a gross annual amount of less than EUR 100,000;
- they are spouses who are not separated, one of whom is a resident taxpayer and the other is a non-resident who chose to be taxed jointly in Luxembourg, provided that the resident taxpayer has earned 90 % of the household's income during the tax year;
by taking into account the income and expenses from 1
January to 31 December of the tax year.
Adjustment of tax withholdings on wages/salaries by way of the annual adjustment procedure
Taxpayers who do not satisfy the conditions for filing an income tax return may, under certain conditions, submit a request for an adjustment of tax withholdings by way of the annual adjustment procedure. If the taxpayer has not been employed as a salaried worker in Luxembourg for 9 continuous months during the tax year, the income and expenses will be taken into account from 1 January to 31 December of the tax year.
In particular, it is in the taxpayers' interest to file an annual adjustment request when:
- they begin their professional career in Luxembourg in the course of the year in which they completed their studies; or
- they work as temporary workers (interim) and have variable or zero monthly earnings;or
- they work in Luxembourg for only part of the year (arrival or departure during the year); or
- they wish to receive certain tax benefits for dependent children.
Forms / Online services
Déclaration pour l'impôt sur le revenu pour personnes physiques résidentes et non résidentes (modèle 100)
Einkommensteuererklärung für ansässige und nicht ansässige Personen (Vordruck 100)
Décompte annuel (personnes physiques non résidentes salariées ou pensionnées non soumises à une imposition par voie d'assiette - 163 NR)
Lohnsteuerjahresausgleich für das Jahr 2021 (nichtansässige steuerpflichtige Arbeitnehmer und Rentner die nicht einer Besteuerung durch Veranlagung unterliegen - 163 NR)
Pour les contribuables mariés : demande de simulation ou d'individualisation / taux RTS
Für verheiratete Steuerpflichtige: Simulation oder Antrag auf Einzelveranlagung / Steuersatz RTS
Who to contact