Originally Posted by
Dr. HFH
I don't think so. I think that the computer systems hold one frequent flyer number per itinerary, so you're left changing it at checkin or at the gate, segment by segment. I credit my AA flights to QRPC so that they're counted by mileage not revenue, and everything else to AA. For my RTW itineraries, I book them using the number I want to apply to the first flight, then change as I go along.
The consensus on the CX board is that while you have FQTV, FQTS and FQTR, there's no passenger-accessible way to code them separately.
On CX a further theory is is to code whatever FQTV you need the status points and miles for, then flash status card at the lounge door.