Originally Posted by
13901
If your trip is on a single ticket your bag should be checked through from AA in 3 to BA in 5. They drive a cart with the transfers from AA to terminal 5 and then the various handlers come and pick up theirs. Having seen it in the flesh it's all very, aehm, rustic compared to Heathrow.
The pick-up-and-re-check ballet is only for the other way round, i.e. coming from outside the US and into the country.
it’s two separate tickets unfortunately. One on avios. One paid. Both BA numbers though.