In reply to keith-ratcliffe:
Your MOT will be extended nearer the MOT renewal date. I had the same problem. To save any problem the garage I use picked up my car and took it away to be serviced and MOT-ed. [I wiped it all down before being picked up and after it was brought back.] This garage has been very good to me over the years and was struggling for custom.
I've heard rumours that insurance companies might be awkward about insuring cars which have had MOT extended. - Or might not pay out in the event of an accident if car with extended MOT was not judged to be road-worthy.
Post edited at 21:13