What are the bank account requirements for the OA non-immigrant retirement visa extension in Thailand?

2nd

Both Tod and Bob are correct. Form doesn't mention anything about overseas requirement for 1 Year Extension. I recently got these forms from CW Office in BKK.

Now as far as what is required for the FIRST yearly extension you would need to have your bank book updated the date you apply <- AND you would need enough updates in your bank book to show that the 800K baht was in the account for 2 months before you APPLY for your extension.

Most banks will give you a 6 month detail transaction record just for the asking (they take a week to get the year usually) so ask for that if you don't update your bank book regularly because nowadays when you update many bank books it only shows transaction summaries (money in/money out) not every transaction that happened since the last update.

You also need the "standard bank letter" that is a 5 or 6 line letter stating your name, the account and the balance on the date the letter was written.

It does NOT state anything about the origin of the funds OR how long they've been in the account.

This is what the standard letter looks like

Okay, let's put this one to bed. There is NO requirement to ever show where the banked money came from on any extension based on being over 50 (retirement) no matter if you're getting that year from an O visa or an O-A visa

The requirement to show that the money came from overseas is when you are using monthly income method and your consulate does not issue in country affidavit of income notary letters, OR when you are initially applying for a 90 day Non-O visa based on being over 50 inside the country at the immigration office

For my first extension based on an OA visa, I got the 12 month statement, but immigration handed it back to me - not needed. Of course, I will need a 12-month statement for my next renewal to prove that I've met the money requirements all year.

For the one year extension of stay based on "retirement", 800K THB must be seasoned in a bank account for two months before you apply for the extension of stay, and three months after you apply.

For the first extension of stay, the money must be seasoned for two months before you apply.