What should I do after being flagged at immigration with a METV while married to a Thai citizen?

VERY GOOD suggestion from Graham Seal ✅

If you'd got a Non-O to enter that would have given you 90 days then you could have done the 60 day Visit Thai Family extension

If you'd got a Non-O to enter that would have given you 90 days then you could have done the 60 day Visit Thai Family extension

Your post suggests that you perhaps have a history of spending time in in Thailand which is no doubt why you were questioned. Having a visa is no guarantee of entry so there's no guarantee you won't be questioned again, or even denied on your next entry. I'd suggest you get the proper visa for the purpose of your visit.

If you don't already have a Thai bank account you won't be able to get a 90 day Non-O visa based on marriage inside Thailand, you'll have to apply outside Thailand and when you return open and fund a Thai bank account for the extension of stay

It’s based on your travel history holding a visa is no guarantee

I'm pleased to hear that you were allowed to enter yesterday on your arrival with a METV multiple entry tourist visa.

I looked at your prior posting history on this forum... none seen. This is your First post on Thai Visa Advice.

You may have posted on another FB forum.

Being questioned by Thai Immigration officers on your arrival yesterday likely is the result of your recent history of entering Thailand and use of extensions and or border bounces.

You were stamped in for 60 days yesterday... AND you can get an ADDED 30 days extension at your local Thai immigration office for 1,900 Thai baht.

That means if you go NOW to deposit the 400,000 Thai baht in a Thai bank account in your name ONLY... You will have met the 2 full months of seasoning required to apply for the Non O Visa as Married to Thai.

Visit your local Thai immigration office now... and get their requirements for the Non O Visa as Married to Thai.

Where are you now living in Thailand?

Which Thai Immigration office will you use?