What are the benefits of having a Yellow House book under my wife's family's name for my visa extension based on marriage in Thailand?

You can't get a yellow book in your Thai wife's 'family name' at all.. it is issued in your own name.. and you can only get it for the address that you have already registered with immigration as your marital home.. to get it your wife has to accompany you to the Municipality.. and she would ordinarily have to produce her blue book and national ID card for the home that you live in.. assuming ownership is held in her name.. the yellow book would then mirror her blue book except it's in your name and has your unique property reference attached to it.. once you have a yellow book you will never have any issues proving your address to any Thai organisation.. such as immigration, airlines, banks, telcoms, the police etc.. however, if the marital home is a rented property that moves the goalposts a little.. because the lease replaces the blue book.. but they will still be looking for uniformity regarding his/hers registered address/es.. in addition the application process requires 2 witnesses.. who must be unrelated Thai citizens.. to sign a declaration confirming that to their best knowledge and belief you are habitually resident at said property.. and your application has to be counter signed by the mayor (or sometimes it's the village head) before it is accepted by the Municipality.. so there are many hoops to jump through.. and remember if you want to apply for it on the basis that you are now living at a relative's address.. you would need to file a change of address with immigration and update your tm30 accordingly.. with all future extension applications being submitted against that address.. there are so many things that could go wrong here that I'd suggest it's not worth going down this route.. mainly because if immigration get even a sniff that you are being dishonest it could prejudice any future extension.. if your documentation is all present and correct then it only takes a couple of hours of your time.. so getting it updated if and when you move should not be overly cumbersome really.. is it worth having.. yes, definitely.. but it's not worth risking problems down the line 😉