General rules
If someone works internationally, the double taxation treaty dictates which country may tax their salary. The general rule is that your salary is subject to taxation in the country where you are physically present when you work.
The salary of a Belgian employee who works in Luxembourg for a Luxembourgian company is therefore taxable in Luxembourg. If the employee works some days at home, however, the salary for the days worked at home are taxable in Belgium.
First relaxation of the rules on homeworking: 24 day tolerance
In the context of international employment, homeworking can therefore have considerable fiscal consequences. In order to address this, Belgium entered into an agreement with Luxembourg in 2015 that an employee could work 24 days from home without consequences for their taxation. The 24 days working from home are then fictively treated as days worked in Luxemburg. As soon as the employee exceeded this ‘24-day limit’, however, the tolerance ends and the homework days are taxable in the country of residence.
Some examples of the 24-day tolerance:
- A Belgian works for a Luxembourgian company in Luxembourg, but works at home in Belgium for 22 days in the calendar year
The 24-day tolerance is applicable, so that the employee’s entire salary is taxable in Luxembourg.
- A Belgian works for a Luxembourgian company in Luxembourg, but works at home in Belgium for 25 days in the calendar year
The 24-day tolerance is not applicable, so that the salary for all 25 days worked at home are taxable in Belgium and the rest of the salary is taxable in Luxembourg.
Second relaxation of the rules on homeworking: 34-day tolerance
From 1st January 2022, the tolerance was extended to 34 days. Put simply, from the income year 2022, the Belgian homeworker in our example can work for a maximum of 34 days from home without fiscal consequences.
Homeworking as a consequence of the corona crisis
For the compulsory homeworking days as a consequences of the measures to combat the spread of corona, Belgium and Luxembourg entered into a special agreement. These compulsory homeworking days do not count for the calculation of the 24/34-day limit.
This agreement is applicable for the period 11th March 2020 to 30th June 2022.
Social security
This tolerance only applies to taxation between Belgium and Luxembourg. Separate rules apply for social security. You can read about these rules in this article, in which we explain more about the rules in respect of social security and international employment.