Whilst the AOPA ground instructor course is aimed at producing PPL instructors trained in a similar manner to Flight Instructors it is not essential, few commercial ground instructors hold such a certificate. The AOPA ground instructor course can be run by any FIC Instructor, and time spent on it can be credited towards the ground elements of a FI(R) course.
Ground instructors conducting commercial training have to have a combination of both teaching and relevant aviation experience; they are then subject to being observed by a CAA inspector, usually during the FTO inspection to give the seal of approval.