just to clear up a few points,
to revalidate your SEP rating you need the 12 hours (6 P1) in the second year with an 1 hour instructor flight. your certificate of revalidation must be signed by an examiner before the rating expires. if you fail to do this then you must
renew your SEP. this is a flight with an examiner, similar to your skills test, but conducted more as a lesson than a check. after this the examiner signs your certificate of experience for two years from the date of test.
your SEP is a rating not a licence.
your PPL licence is valid for 5 years from date of issue and is renewed by paying a fee to the CAA, who then issue your PPL again for 5 years.