What are the requirements for extending a Non-O visa based on marriage in Thailand?

Yes, witnesses are just one of the mountain of things required for the marriage visa. They don't make it easy.

yES

Yes it is required. Also worth noting is that if your marriage certificate is a little bit old (not sure by what time limit) you have to get some paper from your marriage building to confirm is acceptable. All in all this visa is a pain in the arse. Don't think I'll be doing that again.

Yes. It is on the list of requirements at least in Udon. Immigration also visited at our house and wanted a different neighbour there to vouch that we live there. All done. All normai.

The comments already sum it all up very well but I’ll add this:

When they (immigration) came to our house in the village my mother in law and the neighbors got just about every possible answer wrong. It still wasn’t an issue.

They confirmed I do in fact live there, have for a while and that they knew we had been together for a while. So that was all good.

But anything else: where did we get married… wrong. Where did we meet…wrong etc etc.

So should they do that type of interview don’t get too wrapped up in the small stuff.

If u give your address, the next week they send someone to the residence and take a photo of u your wife and any children. I'm going through it at the moment, they came Monday. Also asked for a paper for the registration of marriage, seemingly it only active for 3 months. I have had to do it twice. They may also ask for a update of your bank book more than once until it is granted.

Yes, I needed a witness.

I've never been asked to bring a witness, but always needed a copy of the first page of housebook (tabien bahn) signed by the housemaster, with also a copy of their ID card, stating I live there .

Your personal issue might be that you and your husband aren't listed in the condos tabien bahn. This is in Bangkok though.

To get a one year extension of stay based on marriage to a Thai national, you will need the following.

1. The applicant’s passport and a copy of:

a. The data “picture” page.

b. The most recent visa (if applicable).

c. All entry stamps or extension of stay (if applicable) since arrival.

d. The departure card (“TM 6”) that should be stapled in the passport.

2. The Extension of Stay Application Form (“TM 7”).

3. A copy of the submitted Notification of Residence of Foreigners form ("TM 30”).

4. The Thai spouse physically next to the applicant, and;

a. Their Thai ID card and a front and back copy of the ID card.

b. Their housebook, and a copy of the first page.

5. For male foreigners married to a Thai female only:

a. 400,000 THB in a Thai bank account, seasoned for 2 months or;

b. 40,000 THB in income.

Female foreigners married to Thai males do not need to show income or proof of savings.

6. Marriage certificate (either the rose border certificate issued by the Thai government if married in Thailand, or a translated and certified copy from the applicant’s home country issued by the Ministry of Foreign Affairs), and a front and back copy of the marriage certificate.

7. An updated Kor Ror 2 showing the marriage is current, acquired from the local amphur office for 20 THB.

8. 2x passport sized (4cm by 6cm) photos.

9. 1,900 THB processing fee.

Different immigration offices have different requirements, and may include:

- A hand drawn map to the applicant’s residence.

- Pictures of the husband and wife in various locations in the residence (front of the house/ condo, in all rooms, etc.).

- Rental contract (if renting property or a condominium).

- Witnesses who are familiar with the couple and can verify they live together.

There is an under consideration period for this extension of stay. This may include an at-home visit by the immigration office to confirm the husband and wife are living together, interviews with neighbors, and if using the banked money method, to confirm the money is still in the bank account. The immigration office will give a list of the documents required to bring when the under consideration stamp is closed out.

Yes for some provinces, luckily for us next door neighbour is sister in law.

Problem is if they are not registered at that unit, lots of people register in there home province