Get a new passport as quickly as you can. Show both passports when you enter Thailand by air. Go to immigration after to get the stamps transfered.

@Steve *******

it's not either a visa or an extension. It's a stamp you can get if your application for an extension is refused. It is literally a "extension refused, you have 7 days to leave the country!"-stamp.

No other choice but to leave within 7 days. And you cannot rely on getting the stamp either.

I would go ask immigration with your details of your volunteer work and see what they say, before you plan the change.

If it's an extension you got from immigration in Thailand, and if it's for a reputable organization (the volunteer work). It is possible to just change the reason for your extension. They will cancel your current extension and immediately stamp the new reason (retirement) extension in your passport for 1900 baht. You will lose any remaining days on your current extension and the new year extension starts the day they do it.

If you are on still on a visa, that you got outside Thailand, or the initial 90 day visa gotten inside Thailand (no extensions yet) it is not possible to change the reason for extension until you have had at least one extension for the same reason as the visa was given for (volunteer)

Easiest is just to get married, as long you still have time left on your current stamp. I assume that is a tourist visa? Then when that is close to running out, and you are already married, go get the 60 day "visit family" extension at immigration, to have have enough days left on that to apply for an in country non o based on marriage. Another option, that some have to use because their local immigration will/can not issue the initial non o visa, is to make an appointment at the thai embassy in Vientiane, Laos, and go get the initial 90 day non o there. Or start in Savanakhet Laos with a year multi entry non o based on marriage.

However you can/choose to get the initial non o, it sounds like you already have your ducks in a row to apply for the one year extension at thai immigration after.

Good luck.

@Tore *****************

just confirming that. Didn't try to argue. Sorry if it came off that way.

@Tore *****************

different thai embassies has different requirements. It's not the same. Thailand has 65 different embassies world wide, and 29 consulates, some of which also gives visas.

@Steve ******

not if you have a return ticket within 60 days with most airlines..

@Steve ******

and it might be cheaper to get the visa.. Not sure.. But it could be easier with just an extension depending on your local thai embassy requirements. As said, some require bank statements.

@Steve ******

most airlines will accept a return ticket before 60 days, as once you are here, you can get the 30 days.

But you are right though, if they got a picky airline. Could call and ask them..