I not sure, if this is the correct place to ask, but i not found a better one than this.

My question is, how can i check if the marriage is already registered in Thailand. A few years ago, my wife made a new passport and ID-card (Name-change). And i was thinking, that for this she need to do the registration in thailand. I never have signed anything there. Now i am not sure if we are registered in Thailand already or not.

And if not, what we need to do (is there any advantage except for a marriage visa later on?

Thanks for your responds...

In what country did you get married? Actually, it does not matter. Any marriage outside Thailand is recognised as valid by the Thai authorities. With a Thai translation of the marriage certificate, you wife was able to get her Thai ID card in her married name, and she can do the same for her Thai passport.

I don't think ythe marriage is already registere, but can easely be checked at any amphur.

You register the marriage by having the wedding certificate certified by the embassy of the country you married in. Next you have this translated into Thai by an agency and now you visit the Thai Foreign Ministry, consular section. (the agency can take care of this for you) After being certified by the Foreign Ministry you go together to any amhur to have the wedding recorded in Thailand.

Does it even require a copy of your marriage license ?

I know that they will ask at the amphur at the time of registering your marriage if the women would like to change her surname, but I was under the impression that if a Thai person what to change their name they can just go into the amphur and request it without needing any supporting docs.