Can I change my 180-day tourist visa to a Non-O visa based on marriage in Thailand, or do I need to go to HCM or Savannakhet?

if u do it in Suwannakhet then no need for financial proof. But u will have to do the visa run every 3 months

Required. As man married to Thai woman need proof of financial that that

@Tony ********

mentioned as well . Have to book your appt to make the application first though. So that 15-21 days is for actual process ONCE you already have ur que number to submit which as I said right now depending on location could be a further month or so

Copy of your passport;

Copy of your Thai marriage certificate (both versions);

Copy of your Thai wife’s ID card;

Copy of your Thai wife’s Tabian Baan (House Papers)

Copy of a map to your residence in Thailand;

Copy of photos showing you and your wife together;

Copy of your bank book showing 400,000 THB in your bank account;or

Copy of your income showing 40,000 THB per month in income

As stated the process takes about 3 weeks and you would need to ensure once it is issued that you obtain a re-entry permit to ensure that when you leave Thailand and return that you do not invalidate the extended visa. With this extended visa you do not need to leave Thailand every 3 months to activate another leg of your visa. You only need to report your home address to Thai immigration every 90 days.

yes you can do it in Thailand. go ASAP to ur immigration and you will have to make an appt for application. they say nee 15-22 days min left of stamp allowed to stay in thailand... i jst went yesterday to do mine but the que is so long i have to go back Feb 19th for my application appt.. then they take 1-22 days for consideration to grant the change to non 0 . cost is 2000 baht change of visa applicaton seems to be a very simple and straight forward prcess as far as documentation needed anyway

no agencies that do Savannakhet and no agency in HCMC. However process is straight forward. Both places do not require "show money" in order to get the multiple Non O ( in case you referred to that visa).