Who can complete form 163?

Form 163 is mainly intended for employees in Luxembourg, whether resident (form 163R) or non-resident (form 163NR). It is used to request an adjustment if too much tax has been deducted at source during the tax year.

This form can be completed by taxpayers who are not subject to tax on the basis of assessment, i.e. those who do not file a traditional tax return using form 100. In practice, this often concerns employees whose income is only subject to withholding tax and who do not receive any other taxable income or who are not required to file an annual return.

Form 163 can be advantageous for people who start their professional career in Luxembourg immediately after completing their studies. In this case, the annual tax return can be used to automatically correct the tax withheld, particularly if it does not yet accurately reflect the taxpayer's tax situation.

Finally, this form can also be used by any employee who believes that he or she has paid more tax than should have been due, whether as a result of changes in circumstances during the year (marriage, birth, change of residence, etc.), errors in withholding at source, or to claim tax deductions to which he or she is entitled.

Updated on: 31/07/2025