Can I convert my 30-day visa to a Non-O visa in Udon Thani?

Theoretically one could arrive on the 30-days visa-exempt stamp, and convert (change of visa type) to a 90 days Non-Imm-O marriage visa and from the visa to the 1-year extension. However if you first need to open a bank account after arriving, while the "application for the change" clock is already ticking, you might run out of time. In order to be allowed the application to the "change", you must have a minimum of 15 working days left on your stay permit stamp. It is advisable to start out with a 60-days single entry tourist visa, as this will allow you plenty of time to get your ducks in a row. And keep in mind, for everything you process on Immigration, your marriage must be acknowledged and certified in Thailand and you must show a freshly printed Kor Ror 2 (rose bordered marriage certificate) If you only have foreign marriage documents, they must be certified by the Thai Ministry of Foreign Affairs (which might take a week to process). . . following are the requirements for a "change of visa type" on Immigration based on marriage /6.FOR-PROVIDING-SUPPORT-TO-OR-BEING-A-DEPENDANT-OF-A-THAI-CITIZEN-SPOUSE-VISA-NON-O.pdf

Advice from a fellow aussie, get the 90day Non O from the embassy in Sydney!!!

(makes live a whole lot easier here in Thailand - and will probably save you some coin and headache)

Get the Non Imm O in your home Country. So much easier.

30 day no visa you mean

Non-O based on what and do you have a Thai bank account?

As long as you meet the requirements, you should be able to convert to a non-O visa