Posted on 25 August 2024

The models of tax declarations in Luxembourg: Which forms to use ?

Discover the different models of tax declarations in Luxembourg for 2023. No matter if you are a resident, a non-resident or independent, find the form adapted to your tax situation.

In Luxembourg, there are multiple models of tax declarations which vary depending on the tax situation of a taxpayer.

Form 163 and Form 100 are tax declaration documents which are used to declare your revenues and your deductible expenses. Both forms allow you to apply for reimbursements or to settle unpaid tax debts. Despite their differences, submitting one instead of the other one of the two forms will not alter your ultimate tax outcome.

It is essential to not their distinctions:

Form 163:

Concise version consisting of 6 pages called ‘annual statement’.

Form 100:

Form consisting of 20 pages called ‘tax declaration’.

The choosing of the right form depends on the complexity of your situation.

You have to fill out Form 100:

if your taxable household income exceeds 100.00€ 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
if you are a non-Luxembourg resident, as they are taxed at a fixed rate

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

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 has opted to be taxed jointly and has 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 declaration.

This form is used in particular in the following cases:

in case of a student starting their professional career during the year.
if the taxpayer, employee or pensioner, has had periods of changing or zero monthly remuneration during the year.
if the non-resident employee works in Luxembourg for less than 9 consecutive months during the tax year.
in case 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 local RTS office. To find out which RTS office is relevant to you, you can use our simulator.