Cross-border telework: the 34-day rule
Two different limits apply to cross-border workers who work from home: a tax limit (34 days) and a social security limit (25% of working time, up to 49.9% under the telework agreement). Mixing them up is the most common mistake.
Tax: 34 days
The tax treaties between Luxembourg and France, Belgium and Germany tolerate up to 34 days a year worked outside Luxembourg (telework, but also business trips and training abroad) without changing where the salary is taxed. Beyond the limit, the days outside Luxembourg become taxable in your country of residence from the first day. Your employer may then split withholding, and your home return gets more complex.
Social security: 25% and the framework agreement
Under EU rules you switch to your home country's social security if 25% or more of your working time is there. Since July 2023 a multilateral agreement lets you telework up to 49.9% while staying affiliated in Luxembourg, provided the employer applies for it and the telework is structural. Luxembourg, France, Belgium and Germany have all signed.
What to track
Keep a day log. Count any day with at least some work outside Luxembourg. Many employers cap telework at 34 days in the contract for this reason. The payslip itself rarely shows it; ask HR for the annual count before December.
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Questions people ask
Is a day of training in Paris a telework day?
For the tax count, yes: any working day physically outside Luxembourg counts.
What if I exceed 34 days?
Your home country taxes the share of salary for the days worked there. In France this can be cheaper or more expensive depending on your income; Payslop's Plus report estimates it.
Related guides
Indicative rules as of October 2026. Not tax or legal advice.