The rules for the seasoning of funds for an extension based on marriage using banked money method are 400K baht in a thai bank account in your name only for 2 months before you apply for the yearly extension
MOST offices don't (thanx
@Martin *******
) request you keep the 400K baht in the account during the "under consideration" period from the stamp you get when you apply for the extension. Some do, but it is not an official rule
Once the year extension is inked into your passport there's no obligation to keep the funds in the account any longer.
Where are you in the process of your visa/extension etc???