I’ve never had too much trouble renewing my badge thought I do get a bit hung up on processing times given sometimes as they often state the turn around lag time being up to 8 week so I always put in my application then then get an application form in the post about 3 weeks before renewal tell me I need to renew.
So I always come down on the caution side of things and apply earlier than I should and that said the badge I have now that was renewed this year I got about 2 weeks before the old one expired were all the others have come close to the wire of the expiry of the old badge.