Originally Posted by
mre5765
During the UA to Canada two for one promotion, I booked 4 round trips DEN/YYC, two "free" (i.e. taxes were not free), and two revenue.
....
But they were on a single PNR.
...
The two for ones are a special case -- both parties book into the same fare class -- hence they can be on the same PNR. This is also true for the MP VISA Companion Zone tickets. Key is "same fare class."
Two different fare class tickets (one C, one Y or one W, one K or one paid, one award or ...) can not be on one PNR and two separately purchased PNRs can not be combined into a single PNR.
The use of one or multiple credit cards is not an issue (except can not be done online).