Employee posted abroad: what remains French for social security purposes, and for how long?

A seconded employee retains their French employment contract and remains affiliated with the French social security system. For a secondment to a country within the European Union, the Schengen Area, the United Kingdom, or Switzerland (as stated in the information sheet), the service-public.fr website indicates that they continue to contribute to the general social security scheme and retain their French health insurance coverage. The duration is limited: 24 months "in principle." Beyond that, according to the information sheet on retirement, the employee is considered an expatriate.

This page is based on two fact sheets from service-public.fr, the verification dates of which are given below (May 22, 2024, and September 1, 2025). It does not cover: the duration of posting outside the areas mentioned in the fact sheet, which should be verified with the source; the list of countries linked to France by a social security agreement; step-by-step procedures with the URSSAF (French social security agency) and the health insurance fund; detailed tax information for posted workers; self-employed workers; or public servants. The fact sheets may have changed since their verification date: this page is not a current overview of the law.

Seconded, expatriate: the definition

According to the information sheet on secondment, "a seconded employee is an employee sent abroad by their original employer." The information sheet on retirement refers to an employer who sends you abroad "temporarily." Secondment is a fixed-term assignment, and the employee retains a contractual relationship with their French employer.

The information sheet clarifies that the status of a seconded employee differs from that of an expatriate. For the retirement information sheet, an expatriate is an employee "sent abroad on a long-term assignment or employed under a local contract.".

An addendum to the employment contract generally formalizes the secondment. According to the information sheet, it may specify the applicable law, remuneration, expense coverage, tax implications, and conditions for reintegration. The information sheet also indicates that some countries only grant work permits if an employment contract has been signed with a local company. The employee may receive specific allowances, for example, for housing or transportation.

Social security: what remains French

For a posting to a country in the European Union, the Schengen Area, the United Kingdom, or Switzerland (as stated in the information sheet), the sheet indicates: "You continue to contribute to the French general social security scheme throughout the period of your posting." The employee retains French health insurance coverage.

The information sheet adds that the employee must receive an A1 document: "After approval from the relevant institution, they must provide you with the A1 document (certificate concerning the applicable legislation)." The application process is not detailed here: you should verify this with your employer.

Regarding retirement, the information sheet indicates that the seconded employee continues to contribute to the French National Retirement Insurance Fund (basic pension) and to the Agirc-Arrco supplementary pension scheme, as in France, and that the employer also contributes on their behalf. It specifies: "You are exempt from paying social security contributions in the country where you are seconded."«

The duration: 24 months in principle

Both documents state the same 24-month limit, but do not refer to exactly the same territories. Here they are, as written.

Regarding the information sheet on secondment, the duration "should not, in principle, exceed 24 months." The caveat "in principle" is in the text: the duration applicable to your mission will be verified before departure.

The same document stipulates a waiting period: "Two months must pass before you can be seconded again." It does not specify in this sentence after what duration of assignment this waiting period applies; check this before undertaking two consecutive assignments.

If the mission exceeds the limit

The retirement information sheet states: "Beyond the maximum duration, an employee is considered an expatriate." The rules applicable to expatriates are not detailed here.

Posting outside the EU, the Schengen Area or Switzerland

For a posting of more than three months outside the areas specified in the job title, the posting information sheet indicates that the employee receives, after approval from the relevant institution, a certificate regarding the applicable legislation. According to the sheet, this certificate allows the employee to benefit from French health insurance, and the employee must keep it for the entire duration of the posting. The employer requests a posting certificate.

The maximum duration of these assignments is not published on this page: it must be verified with the official source and the relevant organization before departure. The duration of your assignment is indicated on your assignment certificate.

Upon return: reintegration

According to the information sheet: "At the end of your assignment abroad, you will return to your original company." The employee must be reinstated to "your original position or an equivalent position in terms of responsibilities and salary." The sheet indicates that the employer generally covers round-trip travel expenses. For health insurance coverage upon returning from an expatriation, please see our dedicated page on returning to France.

Taxation: a separate issue

Social security and taxes do not follow the same rules. The information sheet on secondment indicates that the original employer must help the employee determine their tax status in the host country and understand their reporting obligations. Departure may change tax residency status, and the salary may be taxed in the host country depending on the circumstances. This page does not detail these rules.

Texts cited in the information sheet on detachment

The document cites Articles L761-1 and L761-2 and R761-1 to R761-6 of the Social Security Code, as well as the decree of June 16, 2022, concerning the posting certificate (Article R761-2). It also cites Articles L1132-1 to L1132-4 of the Labor Code, on non-discrimination.

Numerical example (fictitious profile)

Situation. Claire, an executive at a company in Lyon, is seconded to Madrid. The assignment begins on September 1, 2027, and is scheduled to last 28 months. Spain is a member state of the European Union (hypothetical scenario). Claire retains her French contract.

Issue. Does the mission exceed the 24-month limit mentioned in the posting guidelines for the European Union?

Strategy. Before signing the amendment, compare the planned duration to the limit and plan what happens for the excess months.

Result.

For Claire, the 24-month period runs from September 1, 2027, to September 1, 2029. The last four months, from September 1, 2029, to January 1, 2030, representing 14.3 days of the assignment, exceed the limit: according to the pension information sheet, she is therefore considered an expatriate. The information sheet on secondment states "in principle," so this interpretation is an illustration that should be confirmed with the source. The applicable tax regime for the four excess months is not addressed here.

This profile is fictitious: the country, start date, and 28-month duration are hypothetical. The calculation is based on adding months (24 months after September 1, 2027) and dividing the durations (4 / 28 = 14.3). It does not predict your specific situation.

What changes depending on your situation

• The host country : European Union, EEA, Switzerland, United Kingdom, country linked to France by a convention, or other country.
• The expected duration of the mission compared to the 24 months, and any previous assignments (the sheet mentions a period of 2 months before a new secondment).
• The content of the amendment Applicable law, remuneration, fees, reinstatement.
• Your tax situation, which does not follow the social security rules.

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