Originally Posted by SPIT
Yes, you are eligible to receive miles on the NW operated flights (not the MA flights). Since you need seperate segments to be credited to different accounts, I'd suggest that no FF# be attached to the reservation. Then hold onto your boarding passes and send them into the respective FF programs. Some programs gets a little snippy about crediting you miles if they see another program's FF# printed on the boarding pass.
AS was initially not going to give credit for a NW flight as I had changed FF #'s in mid itinerary. I would agree with the above, put NO number in and submit your boarding passes.