Originally Posted by
Kwanger
As some of the others have said, when booking avios award tix (I also have a sizeable stash of Avios due to lot of flying paid QR J in previous years at a different job), to get your AA status benefits you just need to put in your AA FF# on your BA booking. Note this can sometimes be a bit tricky as I have found if you book as yourself via your BA account it hardcodes in your BA# as unchangeable (but can be gotten around by going to another OW carrier site such RJ or Finnair and changing there, or at least clearing the FF# then going back to BA's 'Manage a booking'). To avoid that hassle, I've found it is much better to create another passenger (with your own name) and then use the drop down to select yourself - then later, when you get the booking, on 'manage a booking' you can input your AA#. Similarly, if you were to start collecting BA avios/tierpoints on paid bookings, you can still get in the lounges by way of showing your AA card at the airport - but I can't see a good workaround whereby you get to pick your seats free and ahead of time (via inputting your AA status number), then changing your FF# back to BA. I guess it may be possible at a BA check in desk just prior to boarding - I may ask later this month when I'm bouncing back through the First Wing at Heathrow T5.
This is actually very helpful. I've always been under the impression that you couldn't just flash your AA Plat card at the lounge, I thought the card number (FFN) also had to be on the booking, but perhaps if this is not the case then the impact of moving to BA status can be mitigated from a perks perspective. So lounge access is covered.
I have found that you can switch your FFN number back and forth using the RJ site at will, and the status benefits of this update immediately on the BA site. So for example if you book a flight on BA with your BA FFN with no status and can't select good seats, just leave the seat selection as is, then go to RJ and switch it to your AA status FFN, go back to BA manage my booking site and voila, suddenly you can select any seat on the plane. You can then go back to RJ and switch it back to your BA FFN and your seat selection is still honoured (but you now can't change it again). So seat selection is covered.
I don't know what the cut-off is for being able to change the FFN on the RJ site - but potentially you could go to check-in using your AA FFN, this would give you fast-track security and your priority boarding group on your ticket. If you then changed it back to BA FFN immediately after checking in, I doubt this would trigger a reissue of the boarding pass so you'll keep that perk for the journey.
The only thing I think you'd lose is upgrade opportunity as I suspect you'd need to have your BA FFN in the system at the point of boarding. But who knows... it might still be possible to change it on the in-flight Wifi. We will have to experiment.