Originally Posted by
Often1
There are no separate terminals at IAD. All gates are on the sterile side of a single set of checkpoints and all check-in counters are within relatively easy walking distance of each other. If by some chance, UA checks your bags through, then you will simply head from your arrival gate to Concourse B via walk, AeroTrain or moon buggy as the case may be. If your bag is not checked through as I suspect it will not be, then you will need to head to baggage claim, grab your bag and schlep it upstairs to AA/BA check in which is further than UA check-in, but not appreciably so.
BTW - Your TA's answer makes zero sense. UA has had interline ticketing agreements with both BA & AA for 50+ years.
Thanks for your help. It looks like I may have to go baggage claim and grab the bag, go upstairs to BA check the bag, go back through security (I am PreCheck tho) and then to BA gate for flight to LHR. Although looking at the IAD map, it looks like I pretty decent airport layout. United Express is generally A gates and BA is generally B gates I believe.
And let me clarify - she said it will likely be two tickets under one PNR because UA and BA/AA don't ticket with each other i.e. they are not partners. But this may be incorrect as you and others have noted.
I'll just have to book the tickets and see if I get multiple ticket numbers or not...