a few years back, here in chiang saen, chiang rai. immigration in mae sai was split off into a local office here for residents in this area (district would be my guess); my good friend . a farang, went for his renewal (his 23rd) locally and was advised that he had an invalid address, that being a guesthouse; he replied :' i am the owner, i have lived there exclusively in the same room for 10 years, she didnt believe him and his longtime thai wife had to come down to the office;

that finally being settled , the immigration officer checked the nightly register copy they get from the guesthouses/hotels and said 'your name is not registered';  at this point my temperamental friend (singapore chinese) was getting testy; things proceeded to spiral out of control when the officer said the bank letter (letterhead local, dated ok) had to come from the bangkok head office, not local; i think she was just acting out at that point;

my question is that of the address: why is a guesthouse address not ok ? many farang use them long term; i have been in this one 3 months as house is being finished;

thoughts ?

Nothing wrong wit an address for a guest house but you need more than a receipt to prove you are living there. A basic month to month rental agreement would be accepted for proof.