@Andy ********
A 12 month “spouse visa” is a non O visa valid for 12 months. A non O visa allows entry for 90 days. After 90 days the holder must leave thailand and reenter to activate the next 90 day period. Time it right and you can get almost 15 months from that visa.
The advantage of this visa is that you do not need funds in Thailand to obtain it. The disadvantage is having to bounce every 90 days.