Can I extend my B-A visa in Thailand in early 2025, and for how long?

Don't leave Thailand without a reentry permit if you want to keep that Feb stamp alive.

You got a second year using the multiple entry one year B-A Visa by doing the border bounce at Nong Khai on 7 February.

Suggest you ask your Thai Immigration office for their requirements for any extension and or new application for the B-A Visa.

There would be no 30 day extension, and IF it could be extended it'd be for a year based on the terms they issue that visa for.

Personally I've only seen Australians on a B-A visa and I always thought it was some reciprocal visa deal with them and thailand.

AND

To be honest, I have never heard of anyone getting an extension on one.

I imagine the first step would be to go to your immigration office where you do 90 day reporting, have your TM30 filed show them the visa and ask if it can be extended and what the requirements are if it can.

At least you have a while to sort it out 🙂

You're Done with that B-A visa for business in Thailand.

You will need to leave and apply for a NEW THAI Visa if you want to stay in Thailand.

"2.2 Non-Immigrant Visa category B-A (Business Approved Visa)

The granting of such visa to qualified applicants is under the jurisdiction of the Office of the Immigration Bureau in Bangkok. The applicant’s associated company in which he or she will invest in or conduct business with may apply for this type of visa on behalf of the applicant at the Office of the Immigration Bureau. Once the application is approved, the Immigration Bureau will advise the concerned Royal Thai Embassy or Royal Consulate-General via the Ministry of Foreign Affairs to issue the visa to the applicant. The holder of this category B-A visa will be permitted to stay for a period of one year from the date of first entry into the Kingdom."