Quote: Bahston said: What Cruzer said. Verify that your number is in your profile. Also, whenever you make a reservation, verify that the number is in the PNR, and add it if necessary.
And do this before you make the reservation. Doing it after the reservation but before you print the boarding pass won't work, I've been told.
I think it *can* work. I think you just need to do it before you check-in/print boarding pass. I had a reservation with American and I called them before I checked in for my return flight and was able to add my KTN.