Hi Willowtree
The DWP advise that this should not be done. It could cause a lot of problems in the future. The DWP response is that if you cannot maintain your own UC account then you should have a telephone based claim. If your disability prevents you from operating a UC account and a telephone claim then you should consider making someone ( your sister ) an Appointee.
David
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
