I'm currently in the process of applying for the police but the recruitment process here is painfully slow.
Taken this from the west yorkshire police site:
Education & Skills
Qualifications are not a requirement for appointment but for training andeducation, we may also ask for a referee from the relevant institution.
development purposes you will be required to produce examination certificates if
recommended for appointment. If you are still in, or have recently left, full-time
Like you say, all forces vary on certain points but I think this will be pretty standard across the board.