Originally Posted by
warbo
I don't know about other airlines, but certainly with US you can only have one FF number in the PNR. I may be wrong, but I don't think any other SA carrier can have multiple account numbers in the same PNR either. You make a booking, and decide to which account your miles will go, end of story.
I believe you are correct as far as the PNR is concerned but I have always been able to switch at check in. For example, I travel a lot on the UA/EK RTW tickets and it always shows at check in my UA MP number but when checking in to my EK segments I just change it there and it always works. Check in is the place to get it right as it will show on your boarding pass and typically you should be good from there. I think some programs will not adjust after the fact so if you check in with one number and then try to get them to change it later it can be difficult.