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How to fill in your tax return in Luxembourg?

Most Luxembourg citizens and cross-border commuters are required to file a tax return in Luxembourg every year. This declaration is a way of reducing your tax burden by deducting various expenses.

Luxembourg has a reputation for being less complicated than its neighbours, but questions remain. This article describes the most important rules in this area.


Dates and deadlines

From the tax year 2022 onwards, the deadline for filing returns for corporate income tax and business tax is 31 December of the year following the relevant tax year. And in principle the Direct Tax Administration does not accept forms (100 and 163) after this date.

In January or early February, you will receive a tax deduction slip from the tax authorities. This document, which is sent to your employer, is used to deduct tax at source from your salary.

How to fill it in?

The paper Form 100F is still available, but is gradually being replaced by electronic exchanges.

Online, you have two choices:

In both cases, you will be asked to log in using a Luxtrust certificate, to ensure maximum security.

Points of attention

There are a number of expenses that can be deducted, some examples are listed below.

  • Obtaining costs (expenses related to the exercise of an employed activity)

  • Divorced spouse's pensions, alimony or other permanent pensions

  • Compulsory social security contributions and levies

  • Insurance contributions and premiums (home liability, car liability, mutual insurance, etc.)

  • Premiums paid to an old age pension contract

  • Contributions to a housing savings plan

  • Contributions to a supplementary pension scheme, donations or gifts, etc.

  • Domestic and childcare costs

Tax benefits of insurance products

Life insurance and pension products remain the best way for many taxpayers to benefit from various deduction limits.

Insurance products have two tax advantages:

  • Premiums are deductible

  • Maturity capital is exempt from income tax, with the exception of pension income

Which banking and insurance products are deductible?

* In order to benefit from the tax advantages provided for by Luxembourg law, life insurance policies with a savings component must have a minimum duration of 10 years.

** 2 conditions: minimum duration of the contract: 10 years and the term age is minimum 60 years and maximum 75 years.

Cross-border worker

Are you a French or Belgian frontier worker and would you like specific information on your obligations or possible deductions? Consult the tax guide. (


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