A search term from yesterday.
Simple Answer: Yes
Longer Answer: the P Company course, officially the All Arms Pre-Parachute Selection (AA PPS) Course, is open to all officers and other ranks across the UK Military.
P Company is an ADQUAL (additional qualification), it is not a mandatory career course but can be career enhancing (it opens doors to jobs an officer/other rank would otherwise not have access to). An officer will not lose or gain rank because they attend P Company.
Typically, an officer will attend P Company as a junior officer (2nd Lieutenant, Lieutenant or Captain) and once qualified will fill a post suitable to their rank. A minority of officers will never serve with Airborne forces and it is very unusual for officers at the rank of Major to attend (though not unheard of).
Signals officers are posted to 216 (Parachute) Signals Squadron which operates cutting-edge communications and information systems (CIS) at the tactical, operational and strategic levels in support of 16 Air Assault Brigade.