@Mikkel ******
Sorry, the first part is correct, but the second part is wrong! "Only way without exiting Thailand, would be to deposit 800K in a Thai bank in an account in your name only, and buy the 90 day non o directly at an immigration office here." . . he is on a touristic entry and CAN'T get a bank account opened. Firstly he MUST exit Thailand and re-enter using the 90-days Non-Imm-O Visa. Only stamped in on this Non-Imm-O visa, he can get the Thai bank account opened, deposit the 800K, and as soon as the money was in the account for 60 days, he can apply for the 1-year extension . . . . . . . he can't buy the 90-days Non-Imm-O visa on Immigration, because for this he first needs the Thai bank account. I don't understand - you described everything correctly in the first part, but with the end part of your reply, you are completely lost