If you are a temporary employment agency (‘entreprise de travail temporaire’ - ETT), you must meet the obligation to fill in a DPAE for all your permanent and temporary staff.
With regard to your temporary staff, the user company is not required to complete a declaration: you must complete a declaration for each mission at the time of arranging to recruit the employee (as an employer).
Groupings of employers are also required to fill in a DPAE.