Originally Posted by
guv1976
Are you logging in to your AAdvantage account when booking the AA flight? If so, don't: book as a "guest," and then you can enter any oneworld program frequent-flyer number (and even a few non-oneworld frequent-flyer numbers) in the reservation record.
This works for a cash ticket, but wouldn’t work for an award ticket right? Could he call AA and ask them to switch to his AS number after booking?