Originally Posted by
vkng
the way that I've seen UA.com work is that if there aren't enough tickets in a fare class for the whole PNR it moves all passengers into the higher fare class.
This is generally how airline reservation systems work. I've never seen a multi-passenger PNR that contains passengers who are on different flights or in different fare classes.
It's true that UA could be a little more user friendly by building multiple PNRs (some in the cheaper fare classes) when you do a multi-passenger search. But this has other consequences because UA offers certain benefits to "companions" on the same PNR.