Must be married to a Thai nationalThis is substantiated through a Marriage Certificate. There are instances (depending on the processing immigration office) when a copy of an Affirmation of Freedom to Marry is also required. This affirmation is obtained by the foreigner from his embassy in Thailand.
Must meet the financial requirement
Security deposit of THB 400,000 in a Thai Bank Account for at least 2 months prior to the visa application; or
Monthly income of at least THB 40,000. A letter from the foreigner embassy has to be shown to verify this income
Supporting documents as proof of the security deposit in a Thai bank are as follows:
Updated bank book or passbook
Bank letter stating that the money had been deposited to the account from an overseas source for not less than 2 months.
Other documents that may be required to be presented:*