It's roughly the differnce between how desperate you are to give it up and how inconvenient it will be for the school. There is no discussion in the STPCD of giving up a TLR, at all. Someone will doubtless post here that you will have to resign your post as TLRs 'go with the post, not the person' but there is no such requirment in the STPCD so do not panic. If your school has someone who can take on the responsibility, there shouldn't be a problem: discuss it with your head, arrive at a mutually agreeable time for oyu to hand over the resposibility and relinquish the pay - thta would be the agreeable way to do it. If your head starts issuing threats, agree to nothing and contact your union immediately.