Originally Posted by
Dave Noble
If it is an AA codeshare at the moment, it will need to be rebooked onto the BA flight number in order to process upgrade unless things have recently changed. I do not believe that AA offers award availability on its codeshares on BA
Q. Can I use miles to upgrade reservations booked through my travel agency or corporate travel desk?
A. Yes, you can use your AAdvantage miles to upgrade British Airways and Iberia flights as well as American Airlines codeshare flights operated by British Airways and Iberia which have been booked through a travel agency, corporate travel desk or any other source. In order to be eligible, your reservation must include at least one flight booked as an AA flight number.