9. Home office

Impact on taxation

Agreement between neighboring countries and Luxembourg

Residents of France, Belgium, or Germany need to be particularly careful.

Luxembourg has signed bilateral tax treaties that limit the number of home office days allowed without tax impact.

The table below summarizes, for each neighboring country, the maximum number of home office days allowed in 2024 before they have a tax impact in the country of residence.

Country	Authorized home office days (2024)
France	34 days/year
Belgium	34 days/year
Germany	34 days/year

Beyond these thresholds, home office days become taxable in the country of residence, which may require additional reporting and tax adjustments.

Tax threshold: 34 home office days

• This threshold determines the taxation of your salary.
• If you exceed 34 home office days in a year, the portion of your salary corresponding to the additional days may become taxable in your country of residence.

For example, if you work 40 home office days, the salary related to these 40 days could be taxable in France (if you reside in France), while the first 34 days remain taxable in Luxembourg.

Concrete example

Camille lives in France and works in Luxembourg. In 2024, she did 40 home office days.

The salary corresponding to these 40 days will be exempt in Luxembourg and will be fully taxable in France, her country of residence. She will need to declare this income on her French tax return.

Impact on assimilation

Assimilation threshold: 50 days

• This threshold is used only to determine whether the conditions for assimilation are met.

• The salary for the first 50 home office days is considered Luxembourgish income for assimilation purposes, even if some of these days are worked abroad.

To be assimilated as a Luxembourg resident, at least one of the following conditions must be met:

• At least 90% of household income is generated in Luxembourg (the first 50 home office days are not included in the 90% calculation).
• Less than 13.000€ net income abroad (outside Luxembourg).
• For Belgian residents only: more than 50% of professional income must be earned in Luxembourg.

For married or civil union couples, it is sufficient for one partner to meet any of these conditions for the household to benefit from assimilation.

Example

Same example as before with Camille, who lives in France and works in Luxembourg. In 2024, she did 40 home office days.

Regarding assimilation, Camille can be considered a Luxembourgish tax resident. Indeed, she worked less than 50 home office days. Therefore, the salary corresponding to home office days is not taken into account for the 90% threshold calculation.

Impact on social security

In general, to remain affiliated with the Luxembourg social security system, a cross-border worker must work at least 50% of the year in Luxembourg.

If a cross-border worker works more than 50% of the year from home office in their country of residence, they will generally be affiliated with the social security system of that country.