Perhaps consider obtaining a Non O-A visa, pay the premiums for Thai insurance, then after arriving you open a bank account, deposit funds, and then convert to a Non-O in country when the Non O-A expires.
Here’s a website that has a plethora of information regarding Thai income tax. Check it out. They have a great handbook you can download. Look specifically at double taxation agreements, what constitutes a Thai tax resident, etc.
will you be in Thailand more than 179 total days in 2025. The answer to this one question will determine what happens next!
I think this may have been stated more directly by Bangkok Bank as follows: “Bangkok Bank will require that the account holder has held these funds in the account……..”