Digital··4 min
Cross-border workers in 2026: the thresholds every Luxembourg employer must check
Nearly one employee in two in Luxembourg is a cross-border worker. Employers and HR directors must track three specific obligations: the tax threshold for teleworking, the declaration to the CCSS and the 50% social security threshold.
Translated from French · Lire l'original en français
Nearly one employee in two in Luxembourg is a cross-border worker. For an employer, this is not just a statistic: it is an exposure to be managed, with specific tax thresholds and social security obligations to monitor for each employee living in France, Germany or Belgium.
Your actual exposure to cross-border workers, in figures
In the fourth quarter of 2024, Luxembourg had around 489,000 employees, including nearly 230,000 cross-border workers, according to STATEC. Nearly one in two employees working in Luxembourg therefore lives outside the country, which makes cross-border compliance unavoidable for almost every employer, whatever its size. Of this total, around 126,000 cross-border workers live in France, a figure close to the one put forward by the IGSS for 2024-2025, or around 54% of all cross-border workers, according to the STATEC Regards on cross-border workers' pay.
The trend differs depending on the country of residence. In January 2026, inflows from France rose by 3.5% year on year, or around 4,270 additional people, while the German contingent fell by 0.7%, around 330 fewer workers. An employer recruiting on the French side should therefore expect growing pressure on cross-border headcount, while the German talent pool is shrinking slightly. To follow these changes month by month, the IGSS monthly dashboard, fed by CCSS data, remains the reference to consult regularly.
The teleworking tax threshold to build into your internal policy
Since the amendment of 7 November 2022 to the France-Luxembourg tax treaty, signed at the Luxembourg Ministry of Finance and brought into force through French decree no. 2025-382 of 28 April 2025, a cross-border employee living in France can telework up to 34 days a year without those days becoming taxable in France, compared with 29 days previously. Beyond this threshold, it is not only the excess day that falls under French taxation: all the days teleworked in the year become taxable in France from the first day. This rule, set out by the Luxembourg Ministry of Finance, justifies tracking each employee's teleworking days individually rather than applying a generic policy to all cross-border staff. Further reading on this topic: Company mobility plan.
For employees living in Germany, the treaty threshold generally cited remains set at 19 days a year, a figure to be checked against the Luxembourg-Germany bilateral tax treaty at the time it is applied, as the available sources are not as directly consolidated as they are for France.
| Country of residence | Teleworking tax threshold | Consequence if exceeded |
|---|---|---|
| France | 34 days/year (since the amendment of 7 November 2022, applicable through the decree of 28 April 2025) | All teleworked days taxable in France from the first day |
| Germany | 19 days/year (threshold to be checked against the applicable treaty) | Taxation shifts to Germany, to be confirmed according to the text in force |
The CCSS declaration and the 50% social security threshold
The tax side does not cover the social security side, which falls under a separate framework. Since 1 July 2023, every Luxembourg employer has been required to declare its cross-border employees' regular teleworking to the CCSS, as the CCSS press release of 20 June 2023 points out. This declaration does not depend on the number of days teleworked: it applies as soon as cross-border teleworking is regular.
On the same date, 1 July 2023, a European framework agreement on cross-border teleworking in social security matters came into force. Subject to a voluntary declaration by the employer to the CCSS, this agreement allows the employee to remain affiliated to Luxembourg social security up to a teleworking volume of less than 50% of working time, well beyond the usual European legal threshold of 25%, the CCSS states. This increase to 50% is neither automatic nor mandatory: it requires an explicit declaration by the employer, detailed on the CCSS employers' page and restated by the Ministry of Health and Social Security. Without this declaration, an employee exceeding the 25% legal teleworking threshold risks being moved to the social security system of their country of residence.
What an employer should check before the end of the year
Three separate procedures, tax and social security, apply in parallel for each cross-border employee and must be tracked individually rather than through a general company policy. In practice, this means:
- Recording, country of residence by country of residence, the number of teleworking days worked by each cross-border employee in the current year
- Comparing this count with the applicable tax thresholds, 34 days for France, 19 days for Germany, before they are exceeded
- Checking that all regular teleworking has been declared to the CCSS, and starting the voluntary procedure to benefit from the 50% social security threshold if the teleworking volume warrants it
- Updating employment contract amendments or internal teleworking policies accordingly
These thresholds and obligations change as bilateral treaties and European framework agreements evolve. They are in no way a substitute for individual tax or social security advice, as each cross-border worker's situation may depend on specific features of their contract and residence.
