You continue to benefit from the French social protection system and you will pay your taxes in France (if France has signed a tax treaty with your host country). Indeed, according to the provisions of Article L. 761-1 of the Social Code, seconded employees are deemed to have their residence and place of work in France. Consequently, seconded employees are considered not to have left French territory and the French social protection system will apply to them.
At the end of your assignment, you return to your original company, the employment contract of the seconded employee having never been terminated or suspended.
The maximum period of secondment of an employee from one Member State of the European Union to another Member State of the European Union shall, in principle, be 12 months, renewable once if the mission has not been completed as a result of exceptional circumstances (Articles 14 and 17 of Regulation (EEC) No 1408/71). However, it is possible to obtain extensions for a maximum period of 5 to 6 years.
The maximum duration of an employee's secondment from a European Union Member State to a non-EU State is often provided for in bilateral social security treaties. Example: in the United States, the secondment is for a period of 5 years under the bilateral agreement concluded with France.
In the absence of a bilateral agreement with France, the provisions of French law shall apply. By application of Article L. 761-2 et R. 761-1 of the Social Security Code, the maximum duration of the secondment is 3 years, renewable once, i.e. a maximum duration of 6 years.