I went to Samut Prakan last week for the same thing. Because it was my first time extending I had to take a Thai witness who was not a relative of my wife. I didn’t know that was required and had to go back the next day with a neighbour.
I’m not sure if that is a Samut Prakan rule, or if it’s the same at all immigration offices...
my ultimate goal is to get the multiple re-entry permit, as I usually work abroad on a 6 week rotation. Do you know if I can apply for and receive it on that day, if my extension is approved?
I was stuck outside the country for 6 months due to Covid. Now the embassies only issue single entry non-O’s. I’ve been getting multiple entry visas every year for the last 14 years without a hassle. But now it’s a nightmare, unless I can get this multiple re-entry permit 🤞🤞