I have retirement visa valid for 10 months left,i am registered by my address in chiang mai,at the moment i am living in udon thani province,i need to get a residence certificate to buy motor bike,now if i can get rental contract for accomadation in udon do i have to change address from chiang mai to udon,or wait to do my 90 day report and register in udon,or go back to chiang mai and buy? any advise will be appreciated .? Thank you.