While your wife is in her home country make sure to get your marriage certificate verified both by your government and the local Thai embassy. Then when back in Thailand translated and verified by the ministry of foreign affairs.
We had a lot of extra stress not doing this before arriving in Thailand.
this is the one I used . But there are several on the same street . They all look a bit sketchy on first appearance. This one looked less sketchy 😆 and did everything we needed . I can't remember the exact cost but I think it was equivalent to 1000 baht ISH 🤔
Took 2 days for a 90 day visa for me. Use one of the agents . They are really cheap and not only check your forms etc but taxi you to and from the consulate and retrieve your passport the next day so it's super cheap when you factor in the taxi fare.
from what I understand. You now have to apply for the trailing spouse from your home country.
I was lucky and my wife got one in Penang just before they stopped doing them.
If you can apply from your home country the marriage certificate will need to be verified by your own government, then the Thai embassy in your country, then in Thailand translate to Thai , then sent to the ministry of foreign affairs in Bangkok to be stamped again .