been Khon Kaen immigration today for residency letter, just one form name/address and passport,at the same time did 90day report same thing TM47 and passport .
I opened a Bangkok bank account with passport and oa visa no problem,K bank next door refused as I didn’t work in Thailand,Krungthai bank refused as my visa wasn’t stamped in my passport,went to k bank in Khon Kaen which is our local big city and refused using my oa visa but because I am married to Thai national they said that was ok and gave me a bank account,it goes to show there’s no set criteria and basically it’s pot luck on the day.