Do I need to keep 400k baht in my bank account for my spousal visa extension in Thailand?

The best practice for changing to income method is simply have the transfers and have the 400k in the bank.

This way if you are for some reason denied, you have the required money to fall back on.

Even one error and you would be denied.

They can even ask to match your foreign transfer accounts to prove origin of the funds.

I've seen/helped match thai account statement and foreign account statements, to prove origin.

It is not the "norm" but a exception.

The income method for marriage is usually work permit and preferred.

I did 1st year marraige visa 400.000 baht

2nd year i did on 40.000 baht every month . Udonthani

We tried to open a second bank account recently, but were not able. All banks asked for 1 year visa extension

The only account we could open was Kasikorn with the non O visa

Just pay an agent 15k to do your 1 year extension on your Non-O

First of all, you won't be getting the spousal visa in Thailand, because the non-O IS the marriage visa. It's literally called a non-O VISA. In Thailand you will be applying for extensions, not visas.

Second, you are mixing up marriage and retirement. Retirement extensions require money to always be in the bank, but marriage does not.

The requirement for a marriage extension is 400,000 baht in your Thai bank account for 2 full months already at the time you apply for the extension. Once you receive your extension (after the under consideration period and possible home visit), you can then use the money for whatever you want. You just need to have the account back at 400k another 2 months before you submit your application for your next extension.

You need to check with your immigration office when you arrive in Thailand to see if they accept the monthly transfers as proof of income. There are some immigration offices that will only accept "monthly income" if it's the paycheck from your work permit job in Thailand. So if your office is one of these offices, they will not accept your monthly transfers.