@Dominic ***
you need to have the 800K baht in a thai bank account in your name only when you apply
works like this
you put the 800K baht in a thai bank account in your name only
you apply for the Non-O 90 day visa
you get that and wait until the 800K baht has been in the account for 2 months and then you apply for the year extension
ONCE you get the year extension you need to keep the 800K baht in the thai account for THREE months after that and then the balance can't go below 400K baht the rest of the year