GAW:
Ideally you need to get your rating revalidated (by an examiner, there shouldn't be a charge) before it lapses.
Once it has lapsed you can't fly until you have renewed the rating.
Renewal just requires you to fly a skills test which will probably take about 50 mins (if everything goes well); there will be a test fee of around £75.
You do not need to "apply again to the licensing authority" and if you do they will not "allocate you an FE"
As usual with all such queries, LASORS is your friend.
(This all assumes that you have a JAR rating, in the UK)
HFD