What documents are required to extend my visa in Thailand based on marriage, and is an English marriage certificate from Australia acceptable?

To extend your visa in Thailand based on marriage, you need to ensure that your foreign marriage certificate, if issued outside Thailand, is legalized in the country where it was issued, translated into Thai, and certified by the Thai Ministry of Foreign Affairs. An English marriage certificate from Australia may not suffice without these steps. For Australians, the process involves authentication of the marriage certificate at the Department of Foreign Affairs and Trade (DFAT), followed by legalization at the Thai Consulate.