Originally Posted by
flying_q
I do agree that it is impossible, but...
Last winter I purchased 2 J seats (supercheap I fares) from JFK-BRU. I paid for one ticket entirely with vouchers, and another with an unused ticket and cash. Due to the complexity of the purchase, I could not buy them on the same PNR. A few hours after the tickets were issued I decided I wanted to extend the trip a day. I called up the diamond line, gave the agent both PNRs, and he immediately reissued the tickets on one PNR with the new outbound flight. No change fees.
This is because the agent you talked with the second time rebooked both passengers into a new PNR. I am sure that the new confirmation number/record locator number/whatever you want to call it was different than either of the first two confirmation numbers. Just as it is not possible to combine two separate PNR's into one, it is not possible to increase the number of passengers traveling in any single PNR.