in my opinion, use it for as long as u can get away with it!! as long as u realise its very possible at some point that youll get caught out and u dont mind havin the account closed, i had mine closed a while back, i knew theyd find out sometime but it was just so much the easiest way i decided to use it until then, they were actually very good with me, allowed me to withdraw all the money i had in there right away! but of course they might not with u!