Bank Account

Afternoon
I am appointee for my son who is Autistic age 33 .All his benefits go into my bank account and if anything happened to me he would be unable to access his money. I cannot open him a bank account of his own because he hasn't got any form of id passport driving licence etc any letters that refer to him are all addressed to me and they wont accept them. I even explained to DWP requested letters addressed to him but when they arrived they were still addressed to me Unless there is another option the only thing I can think off is to stop being is appointee then all his letters etc are addressed to him but I know as soon as I do that they stop his benefits until it is sorted out. Has anyone else had this or found another alternative .Many Thanks