Upvote:1
Registered Traveller status is valid for 12 months from the day you submit your application:
The immigration officer will check that you meet the criteria and tell you if you can become a member. Your 12 month membership will start on the day you submitted your application.
After that, you need to renew your application on a per-year basis by paying additional fees. At this stage, I assume you need to prove / meet the same criteria as for normal applications which is "at least 4 visits to the UK in the past 24 months".