@Ervin ******
here's the list of documents you USED to need to provide at Savannakhet to get the year long, multi entry Non-O visa (I say used to because no one knows if they're still gonna sell visas the way they did before this covid shit storm happened)
These are the documents you need at Savannakhet:
-the original rose bordered marriage certificate
copies of:
-front&back of the rose bordered marriage certificate
-front&back of your thai spouse's i/d card
-thai spouse's house book listing
-data page of your passport
-lao visa & entry stamp
you also need 2 passport sized photos,a filled out application along with 5000baht.
Your thai spouse signs the things with their name on them, you sign the things with yours <- meaning you BOTH sign the marriage certificate copies ;)
NOTE: if your thai wife changed her name (took your surname when she got married OR after that) you need the certificate stating she changed her name too..