Article R1263-3 of the French Labour Code
An employer who posts one or more employees, under the conditions set out in 1° of article L. 1262-1, must submit a declaration containing the following information: 1° The name or business name as well as the postal and electronic addresses and telephone numbers of the company or establishment that usually employs the employee or employees, the legal form of the company, its individual tax identification number for the purposes…