@Warin *********
Once your in Thailand you can if you wish convert your retirement non O to a marriage visa but you'll have to book a visit to the british embassy in bangkok,Than get a affirmation of marital status and copy of your British passport signed and certified with stamp and stickers once you have them get them translated into Thai..When you get them back from ministry of foreign affairs goto your local district office and get married..Once you have done all that go back to immigration and start applying to change from retirement to marriage...🙂🙂🙂Retirement way is much easier but you'll need more money in bank or a monthly income,Yes marriage one needs a lot more paperwork doing but it's not that hard if you just sit down and go through it all one bit at a time..Just done my first one and had no problems at all..🙂