Originally Posted by
trueblu
I _think_ you could upgrade using AA miles if booked into W...but you would then end up crediting to AA I guess, so not that helpful..
tb
Its perfectly fine to use AA miles to upgrade a BA flight and then credit the flight to BA. But the same flight could also be upgraded with Avios.
The main challenge is that you need to be booked in Y or W (not E or T, the affordable premium Economy buckets).