Succession (sp) In Japan, in cases where a family has no male heir, if a girl with no brothers weds, the adopted son in law sometimes takes the family name of his wife. Is there a similiar cultural concept in Thailand at all or is this unheard of?

Never heard of it.

Be aware, family names/surnames are a relatively new concept in Thailand.

Never heard of, but now a woman can keep her own last name if getting married and any children from the marriage can I presume choose their last name. (Not sure about this last). That should be the way to preserve the family name.

Never heard of it.

Be aware, family names/surnames are a relatively new concept in Thailand.

I see. Thanks. When I get re-married I am changing to my Wife's last name legally through the US court system.

Just wondering how I am going to explain this to Thai Immigration, land office, Bangkok Bank mangement, etc.

If it was a so called "Gay marriage"

(Equality under law without discrimination based on sexual preference) perhaps that might be easier to explain.