What documents and forms do I need to extend my Non-Immigrant O spouse visa in Thailand?

If your wife changed her name all this paper to and what Tod saying best going there every year before you going I was going this year with same paper as last year and changed again and immigration say by her self better come before here and ask what you need good luck👍

You'll need to meet the financial requirements of banking 400K baht in a thai bank account in your name only for 2 months before your application for extension

OR

you'll use a notarized affidavit of income from abroad letter from your consulate stating you get 40K baht a month in income,

Then you'll need the original marriage certificate (Kor Ror 3) and the Kor Ror 2 (the one that looks like a form), and copies of the, along with copies of your thai wife's i/d card, her house book listing, your lease, possibly your affirmation of freedom to marry, and photos of you and your wife in front of the address numbers of where you live, a couple pictures of the wedding if you have them, a couple pictures of you and her sitting in the house, a hand drawn map to your place,

AND

you might need more than just that. It's about all I can remember off the top if my head.

That is exactly why I said GO to the immigration office BEFORE you need to get your extension and get the hand out from them that lists everything. The last thing you need or want to do is to make 3 or 4 trips there because you're not prepared documentation wise.

At most immigration offices you can apply for a yearly extension of stay when you have 30 days or less left on your current stamp. There is NO reason to wait until your stamp is almost expiring because the ADD the year onto your current expiration date.

I would say stop by your immigration office and get the hand out of exactly what they require document-wise to get the extension of stay from them

I say that because the fact you had the documentation to get a Non-O vias based on marriage from a thai consulate does NOT mean you have the documentation to get a yearly extension of stay from the immigration office. They are two completely different government offices run by different agencies and the documentation requirements are not the same.

Good Luck (y)

You use form TM.7 application for extension of stay. Your application for a yearly extension will go under consideration for 30 days then you go back and get the extension inked into your passport, after that IF you need a re-entry permit you can buy a single for 1000baht or a multiple for 3800baht