Can I Change My Non-B Visa to a Non-O Marriage Visa Myself?

@Steven ********

I deleted it, you do not know if the OP can get a Visa Exempt Entry. He is on an Extension of Stay based on working, which has to be cancelled at Immigration before making a border run.

Your Idea:

Visit Immigration and cancel your stay

Go on a border run (if possible with the passport)

Conversion to new Non Immigrant O visa, cost 2.000 Thb

After 60 days, apply for Extension of Stay.

My idea: cancel current Extension of Stay and apply for new one, save a lot of money, visits to immigration and possible border run or fly out or even go back to home country first.

You have the Extension of Stay based on working, make sure and double check with Immigration that you have all the documents and meet al the requirements for an Extension of Stay based on being married to a Thai National.

Cancel the Extension of Stay based on working, free of charge, apply directly for a new Extension of Stay based on marriage with a Thai National, cost 1.900 Thb.

Application goes 30 days under consideration, go back on that date and get the rest of the year stamped in your passport.