The non-immigrant “O” visa, often known as a fiancé visa in Thailand, is intended for foreign nationals who are engaged to a Thai citizen or permanent resident and want to live with their fiance in Thailand for a prolonged period of time.
In order to be granted a fiance visa in Thailand, you must fulfill the following conditions:
You must be engaged to a permanent resident or citizen of Thailand.
You must present a passport that is current and has at least six more months of validity.
To be sure you don’t have any contagious diseases, you must get checked out by a doctor.
To demonstrate that you don’t have a criminal past, you must have a police clearance certificate from your home country.
You are required to present evidence of your relationship with your Thai fiance, such as pictures and written communications.
You need to present an official document from your Thai fiancé’s workplace attesting to their employment and compensation.
Once you have met these requirements, you can apply for a fiance visa at the Thai embassy or consulate in your home country. After the initial 90 days have passed, you can ask for a stay extension at the nearby Thai immigration office.
It is important to note that the fiance visa does not permit you to work in Thailand. You must get a work permit separately if you want to work.
This information should be useful.