CPilotUK,
You are spot on on the first part, but there is a 2-year time limit from completing the last exam to applying for your licence (this implies that the skills test has been done).
That is, the set of completed exams is valid for 2 years (from the date of the last exam) and your licence application must be received by the CAA while the exam set is valid.
Unless it has been changed very, very recently!
SD