Which form should I submit between 100 and 163?

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Important! The taxx.lu system will indicate (after payment) which form you need to submit for your tax situation. Only one of the two forms needs to be sent in!

Form 163 and Form 100 are tax return documents designed to declare your income and deductible expenses. Both forms allow you to claim refunds or settle outstanding tax dues. Despite their differences, submitting either Form 163 or Form 100 won't alter your ultimate tax outcome.

It's vital to note the distinctions:

Form 163: A concise 6-page version, labeled an 'annual statement' (French: décompte annuel).
Form 100: A 20-page document called 'annual tax return' (French: déclaration d'impôt).

Choosing the right form hinges on the complexity of your situation.

You must complete form 100 when :

the household's taxable income exceeds €100,000 per year
in the case of a combination of several forms of remuneration where the taxable income exceeds €36,000 for taxpayers in tax classes 1 and 2 and €30,000 for taxpayers in tax class 1a
for non-Luxembourg residents, where you are taxed at a fixed rate.

Or if your Luxembourg taxable income is not subject to withholding tax, as for example for :

income from the practice of a liberal profession
income from property rental
salaried income paid by a foreign employer or pensions paid by foreign pension funds
taxable income comprising more than €1,500 of net income from transferable securities subject to withholding tax
taxable income which includes more than €1,500 of directors' fees
non-separated spouses, one of whom is a resident taxpayer and the other a non-resident person, who had opted to be taxed jointly and had provisionally obtained tax class 2 on their withholding tax form.

If you do not meet any of the above conditions and Tax Administration has not specifically asked you to submit Form 100, then choose Form 163.

Form 163 or "Annual statement " is a simplified tax return.

This form is used in the following cases in particular:

when a student starts their professional career during the year.
if the taxpayer, employee or pensioner, has had periods of variable or zero monthly remuneration during the year.
Ii the non-resident employee works in Luxembourg for less than 9 consecutive months during the tax year.
in the event of a change in family situation resulting in a tax change, for example, the birth of a child to a single taxpayer with a change from tax class 1 to class 1A during the year....

Form 163 should be sent to your relevant RTS Office. To find out which is your RTS Office, you can use our simulator.