Originally Posted by
guv1976
It is possible, by using the "Manage My Booking" function at finnair.com -- or some other oneworld carrier websites -- to remove your BAEC number from all the bookings. Some people have then successfully added their AAdvantage numbers at the same site; others have just left the site after removing the BAEC number, and then gone to ba.com, pulled up the bookings (now devoid of any FFN), and added the AAdvantage number.
Wow - many thanks. I never would have known. This worked a charm!