Originally Posted by
Marsh11
So how do tools like CheckMyTrip or TripCase figure it out? If you try to enter your locator number, sometimes it finds your record and sometimes it says your airline or travel agency doesn't participate but you can enter your itinerary manually. So there must be some way it decodes them. Or maybe it just tries looking them up in all the different systems to see which one gets a result?
It looks in the system that they use. If the PNR is located in it, then it can pull it up. If it's not in system they use, than you must manually enter. Same reason some airlines can pull up another airlines reservation.