How can I extend a Non-O spouse visa in Thailand, and do I need a Thai birth certificate?

Okay, this turned into a train wreck most due to the O/P not saying exactly what they're doing or trying to do

SO to recap

The O/P entered on a 90 day non-O based on having thai children.

The children were born out of wedlock and that means IF the O/P is gonna use the children as the reason to apply for a yearly extension of stay he needs to get proof of legal parental rights, which you get one of two ways;

go to the amphur with the children if they're old enough (usually 6 or so) and get the decree there

OR

go thru family court and get the decree from the court.

Without having that proof of parental rights a foreigner who has half thai children which were born out of wedlock cannot use them as the reason for their extension.

Another problem was the fact that the O/P mistakenly thought the documentation they showed to get the VISA in a a thai conuslate in another coungtry was the same documentation they needed to get a year extension inside the country at the immigration office.

Those are two completely different processes by two completely different governmental agencies and have nothing to do with one another.

I'd say GO to Cambodia or Vietnam and get ANOTHER 90 day Non-O visa based on being the father of thai children, (again the requirements at the consulates are less than they are inside the country)

Come back get stamped in for 90 days, wait out the time to get the family court decree (that you say is already in process) and THEN apply for the yearly extension

With the (air) borders opening up, it might be worhtwhile to get a multi entry non-O visa from the Ho Chi Minh City consulate. There is no requirement of proof of funds plus the staff are friendly and efficient. I did this in December 2018 and January 2020.

An added bonus is that you can score an extra 90 days by re-entering Thailand on the expiry date of your visa!

@Victor **********

i think you might wanna re-think the "go to Lao for a tourist visa" seeing as the country is closed and instead to go to Cambodia or Vietnam"

Also

As you're the father of thai children, you should be able to get a 90 day single entry Non-O visa based on that with just the birth certificates, the mother's thai i/d and her house book listing.

Check the website of the thai consulate in the country you're thinking of going to and see what the requirements are

BUT

Getting that visa will get you stamped in for 90 days when you show up and then you just wait to apply for the year extension after that 🙂

I tried my local immigration office but they told me i have to go Cheng Wattana building#2 Bangkok and my wife had to go with me go early the door opens 7am

you have to apply for a 1-year extension at the immigration office that serves the area your address on TM30 receipt belongs.

You need to get the latest requirement from your local immigration office. Here is the general information for extension based on raising a half Thai child. (Edited based on new comment below)

You apply for the Extension of Stay based on being married with a Thai National at the local Immigration Office that serves your address.

You need the marriage certificate next to other documents, but there is no requirement to bring a birth certificate.

Best is to contact your local Immigration Office and ask the hand out with requirements.