Basic entrants start as Officer Cadets, graduate and qualified entrants as Fg Offs (for pay & seniority purposes; they're refered to as Studdent Officers while on IOT unless the latest cse changes have affected the nomenclature). Who counts as a qualified entrant varies from branch to branch; for instance, a Member or Associate of the Chartered Institute of Logistics and Transport would be quialified in the Supply branch. There is no qualified entry to the Flying, Regiment or Provost Branches and no qualified entry for civillians to the Engineer Branch.
The relevant payscales at the moment
Fg Off and below ------Daily ---Annual
Level 1 (Officer Cadet) 38.03 --13,881.00
Level 5 (Plt Off) -------60.11 --21,940.20