Does not need one, just police clearance (finger print taken at the police station opp central world and mail it back to your country's police dept handling police clearance.) and a 'Affirmation of Marital Status' from your own country. They need to be stamped by your embassy and translated to thai, than stamped by MFA in bkk. There is a translation shop at the 2nd floor of MFA. (passport needs to be included as well) (bring your half to the khet and ask them what is needed.)