Luxembourg border worker: teleworking and taxes

An employee who lives in France and works in Luxembourg is, in principle, taxed on their Luxembourg salary. Working remotely from France can modify this arrangement, but only beyond a number of days stipulated by the tax treaty: 34 days per year for tax periods beginning on or after January 1, 2023. Previous agreements referred to 29 days.

This page deals with income tax for employees residing in France. Social security benefits follow different thresholds, which are explained on the related page about cross-border teleworking. It does not cover Luxembourg tax (tax brackets, tax classes), the sections of the French tax return, or the situation of a company director.

The principle: taxation follows the location where the employment is carried out

Article 14 of the Franco-Luxembourg convention of March 20, 2018, places salaries in the state of residence, unless the employment is carried out in the other state: in that case, they are taxable in that other state. The French tax authority (BOFiP) (BOI-INT-CVB-LUX-20) expresses this as follows: salaries and wages of private origin "are taxable in the state where the professional activity is carried out.".

The ministerial response published in the Official Journal of April 1, 2025, reiterates that this principle is maintained: the salaries of cross-border workers from Luxembourg sources remain taxed in Luxembourg.

The 34-day threshold and its origin

Point 3 of the convention protocol provides for flexibility. A resident of one state who works in the other state and is physically present in their state of residence, or in a third state, to perform that employment for periods not exceeding a total of 34 days is considered to be working in the other state for the entire taxable period. In other words, below this threshold, the salary remains attributed to Luxembourg as a whole.

This threshold stems from an amendment signed in Brussels on November 7, 2022. It increased the threshold from 29 to 34 days. The amendment applies to tax periods beginning on or after January 1, 2023.

The last line requires clarification. Article 3 of the amendment stipulates that the two states must meet before December 31, 2024, to determine the conditions applicable from January 1, 2025, and, if necessary, conclude a new amendment. None of the official documents consulted mention any text subsequent to the 2022 amendment, and the Luxembourg administration's FAQ gives 34 days for residents of France. For the year in question, please verify that this threshold has not changed.

A clarification regarding the sources: the BOFiP BOI-INT-CVB-LUX-20, in its version of 23/02/2021, still mentions 29 days, while the consolidated agreement, the amendment, and the Luxembourg FAQ give 34 days. This page does not decide between these texts: the figure in effect for the year in question should be verified with the official source.

Remote work, assignments, training: every day outside of Luxembourg counts

The text of the amicable agreement of July 16, 2020, which specifies the threshold details, does not mention teleworking. The Luxembourg administration states in its FAQ that the preceding provisions "are not exclusively applicable to teleworking." Point 3 refers to physical presence in the country of residence or in a third country to perform the job.

How the days are counted

The accounting rules come from the amicable agreement, taken up by the clarifications of the Luxembourg administration.

• What matters : the days the employee is physically present in their state of residence or in a third state to perform their job. Any fraction of a day counts as a full day. Attendance for professional training also counts.
• That doesn't matter : days of attendance not justified by employment, including leave, weekly rest days and public holidays when the employee is not required to work, sick leave and cases of force majeure which are beyond the control of both the employer and the employee.
• The assessment : the threshold is assessed over the year, globally, including if several separate contracts follow one another in the same year.
• Part-time The threshold is reduced proportionally to the working hours stipulated in the contract or the duration of the contract. If the result is not a whole number, the next lowest whole number is used.
• The proof It is up to the taxpayer to demonstrate that they meet the conditions. The supporting documents mentioned range from the contract or certificate from the employer to time sheets, nominative transport tickets, nominative hotel invoices or signed attendance lists (detailed supporting documents are provided in the Luxembourg administration's guidelines).

When the threshold is exceeded

If the threshold is exceeded, the taxpayer loses the benefit of point 3. The amicable agreement specifies that the country of residence regains the right to tax the remuneration "from the first day," based on the actual time worked. The threshold is therefore not an exemption: once exceeded, the first few days are also counted. Overtime pay is taxable in the country where it is earned.

The tax credit on the French side

Legally, the 2018 convention provides for taxation in France, with a tax credit for salaries from Luxembourg sources, rather than an exemption (BOFiP BOI-INT-CVB-LUX-30). The BOFiP states that, for employment income covered by Article 14, the credit is equal to the corresponding French tax, "provided that it is actually subject to Luxembourg tax.".

For a progressive tax scale, the corresponding French tax is the net income multiplied by the average tax rate, resulting from the tax due on the total net income. Luxembourg tax is not deductible.

The old system was tolerated, upon request in the declaration, for income received from 2020 to 2023. The ministerial response of April 1, 2025 states that the 2018 rules apply fully from 2024 income.

Social security, another topic

The 34-day tax threshold is unrelated to the social security threshold. The list of signatory states to the framework agreement on cross-border teleworking, published by CLEISS and updated as of February 1, 2026, includes France and Luxembourg. The conditions are detailed on the related page.

Julien, 35 days for a threshold of 34: numerical example (fictitious profile)

Situation. Julien, a fictional employee, lives in France and works for a Luxembourg company. He works 220 days per year and receives €72,000 in salary. He is single, has a tax allowance, and his net taxable income is treated as this salary. During the year, he worked remotely 23 Fridays from France, spent 8 days on assignment at a client's site in France, and worked remotely for 4 half-days.

Issue. How many days count, and what difference does it make if it's over by just one day?

Strategy. Apply the calculation: 23 + 8 + 4 = 35 days, since each half-day counts as a full day. Adjust this total to approach the 34-day threshold. To estimate French tax, allocate a portion of remuneration proportional to the number of days worked (35 out of 220) to France, then apply the tax credit at the average rate.

Result.

In this illustration, one more day increases the French tax base from €0 to €11,454.55 and the corresponding French tax from €0 to €2,339.27.

This profile is fictitious. The pro-rata allocation of days is a calculation assumption: the amicable agreement refers to attribution "based on actual time worked" without specifying the calculation method in the excerpts reviewed. The tax scale applied is that of 2025 income, before any discounts or reductions. Luxembourg tax on the portion attributed to France is not calculated.

Luxembourg border worker: what changes depending on your situation

• The nature of the days : teleworking, assignments or training count; holidays and sick leave do not count.
• Your contract : part-time work or a short contract reduces the threshold, with rounding down to the nearest whole number; several contracts in the year are assessed together.
• The year in question : the 34-day threshold applies to periods opened since 2023 according to the amendment; the conditions from 2025 onwards are to be verified.
• Your home The Luxembourg tax authorities provide, upon request, for the assimilation of a non-resident to a resident if at least 90% of their worldwide income is taxable in Luxembourg, or if their net income not taxable in Luxembourg is less than €13,000. This procedure is subject to its own rules.
• Your other income : the average rate of the tax credit depends on the tax due on the entire net total income.

The rule depends on your situation. No results are guaranteed.