Originally Posted by
abligh
Once upon a time I had this and passport details permanently in my profile (after speaking to someone on the BAEC Gold line). Then my passport needed renewing and I changed my BAEC profile, and neither KTN or passport number ever stuck again :-/
KTN has never been on BA's or BAEC's systems, to the best of my knowledge. However KTN was / is supported by other GDS interfaces, for example used by a corporate booking system, so KTNs could in certain circumstances populate AA flights on BA bookings. Plus I suspect AA's system had some algorithm on their side of the house for regular flyers. No reason why the passport number shouldn't stick, however, it's best in place before booking, however again a corporate booking system can plonk reservations into life in such a way that they don't read over the BAEC profile information.