No; there’s no joint privileges in Thailand. My wife “follows” or “piggybacks” off my retirement extension because she’s not yet 50 Basically this means we applied for retirement extensions based on marriage and because she’s not yet 50, she didn’t need her own 800K in a Thai bank account but rather, we went to the US consulate to get a standard boilerplate latter that swears we are married. The consulate doesn’t need any proof and in fact is not legally allowed to even look at your marriage certificate because they are not allowed to verify documents issued by a state. So it’s really stupid but it’s basically the honor system. It’s $50 USD for the letter and takes two minutes but you need an appointment so plan ahead. They treat her visa exactly the same as mine with the same retirement privileges and same expiry dates. We both do individual 90 day reporting
I’m also told if you’re not using an agent you should probably bring the original marriage certificate or certified copy.
Go see Jim Tachinamurthy in Penang. He is the resident expert on all visas for Thailand in Penang and got us our non O single entry which we then extended based on retirement. He knows all the rules and has ins with the consulate. You can messenger him by typing his name