In theory, you go back to the entry point to correct the entry stamp.

No downside to going to the local immigration office to see if they can correct your stamp. The worst thing would be they say "No, you have to go to the airport you entered Thailand".

As you have a multiple entry visa, it could be easier just to go border bounce to activate a new entry on DTV than go back to the airport in Bangkok to correct the current stamp.

@Pete ******

, it (short stay at a hotel) wouldn't work for long-term extension at most immigration office. That is a measure only for tourism extensions.

@Lloyd *******

, is it ”free”? I know there is a 1-year extension by proving Thai nationality for the same fee of 1900 baht.

Let's sort some things related your post based on facts.

- Multiple entry is not available for Non-O for any reason through eVisa application

- Non-OA visa is available in your country only (not inside Thailand) and for being over 50 years old

- No RTE/RTCG around Thailand issues multiple entry Non-O based on retirement

- No more "in-person" RTE/RTCG in Southeast Asia as of 1 Jan 2025 (edited)

- You can apply for single entry Non-O based on retirement inside Thailand (by having 800K baht in a Thai bank account) or outside Thailand. Then following 1-year extension for the same reason in Thailand and a re-entry permit

- You cannot apply for Non-O visa based on spouse to a Thai without legal marriage

We are not going to speculate wild options.

@Andrew ****

, Please consider these facts, sort your idea, and make a new posts.

As mentioned, 1-year extension based on being over 50 can be applied 30 days in advance in most provides. Some accept 45 days remaining with your current stamp.

The procedure at the immigration office is on-spot (means within a day, a few hours) at most offices. There could be a few offices that you have to go back in a couple of days max.

Other than that, it all depends on how fast you can collect the necessary paperwork, including the lease agreement, bank letter and transaction record, etc. Technically, it's possible to get it done within a few days trip with being well prepared.

Better to try to contact your local office for their latest requirements in advance for preparation.

Don't forget to apply for a re-entry permit AFTER you get a new 1-year extension inked into your passport.

@Phil *****

, oh, no. Sorry to have to deliver a bad news. In general, you cannot apply for an extension for medical reason if you are on overstay. Medical extension is available only when you are on a valid stamp.

I'm afraid you have to keep on being on overstay until you can leave.

@T**

would confirm this later. Just hoping I'm wrong about this.

Yes, it is possible to apply for an in-country initial Non-O visa based on a parent of a Thai child, if your local immigration office allows in-country visa application. You also need to have the minimum remaining days with your entry stamp to apply for an initial visa.

Go to the local immigration office for their latest requirements for an in-country Non-O visa for that reason. Usually, the funds don't have to be seasoned for the initial visa application for Non-O based on a Thai child.

You don't need a re-entry permit to leave Thailand. But, you need to get a re-entry permit on your passport BEFORE you leave Thailand, to keep your current stamp "alive" and enter Thailand again on it.

Thank you for the update.

You need to check with your local immigration office. Most offices let you apply for a 1-year extension based on marriage when you have 30 days or less remaining with your entry stamp on Non-O marriage. Some offices such as Bangkok, Chiang Mai, Phuket, and a few others accept your application for an extension when your stamp has less than 45 days.

Go to your local office in advance to get their latest requirements for a 1-year extension based on marriage to a Thai. Each office has its own list, including seasoning of funds.