I want to change my Business visa to a Marriage visa. I approached Thai immigration in Nakhon Ratchasima and was told by the immigration officer that the only acceptable proof of financial support was 400,000 baht in a Thai bank account for 2 months. He will not accept 40,000 baht a month income. Regardless of how the law actually reads, with this immigration officer, I only have one option.

So here's my problem. I transferred the required funds into a Thai bank account that is in my name. But my current Business visa will expire before the money is in the account for the "required" two month period. So, what do I do?

Are you on an extension of stay or a 90 day visa entry?

There is a 60 day extension of stay available to visit spouse so if really on a visa entry you should be able to use that to stay long enoug.

You can easily obtain a non immigrant O visa from a Consulate with marriage certificate/copy of wife ID card and home register if you can not do any other way.

If on 90 day visa entry leave the country just before your visa expires and on re-entering Thailand you will get another 90 day permission to stay.

If on 90 day visa entry leave the country just before your visa expires and on re-entering Thailand you will get another 90 day permission to stay.

I'm on a one year extension of my Non-Imm B visa.

You can try to obtain that 60 day extension the day your work ends/work extension ends and that woujld give you enough time. Not positive they will issue from a previous extension so if not plan two to obtain a new visa would work.