A new Luxembourg circular dated 24 June 2026 clarifies a rule that directly affects cross-border workers living in France and their employers. It has a concrete impact on the employee's tax and on the company's payroll management. Here is what matters.
The principle in one sentence
A cross-border worker is taxed in Luxembourg on their salary. But if they work too many days outside Luxembourg (remote work in France, business trips, training), part of their income may shift to French taxation.
The threshold to remember: 34 days
Each cross-border worker may work up to 34 days per year outside Luxembourg without anything changing: their entire salary remains taxable in Luxembourg. This threshold, raised from 29 to 34 days since 2023, provides a comfortable margin, particularly for remote work.
What counts, and what does not
Only days actually worked outside Luxembourg are included in the count. The following do not eat into the quota:
- paid leave;
- weekends and public holidays not worked;
- sick leave.
Conversely, a half-day worked in France counts as a full day.
Beware of the threshold effect
The most important point: if the employee exceeds the 34-day threshold by even a single day, it is not only the extra day that becomes taxable in France, but all of their days worked outside Luxembourg. Crossing the line is therefore costly, which is why rigorous tracking throughout the year is essential.
The burden of proof lies with the employee
The benefit of this rule is never automatic. In the event of an audit, it is up to the employee to demonstrate where they worked. It is therefore necessary to keep the relevant supporting documents: employer certificate, badges or attendance sheets, train tickets, expense reports, mission orders.
In practice
For the employee, this means keeping an eye on the number of days worked in France and properly archiving supporting documents. For the employer, it means reliable tracking of these days, since they handle the salary withholding at source.
At CorExperts, we help managers and employees see clearly: counting the days, securing payroll, building the evidence. For an analysis of your situation or that of your teams, contact us.
Source: circular L.G. - Conv. D.I. no. 61 of 24 June 2026, Administration des contributions directes (impotsdirects.public.lu).