Old Sep 16, 20, 9:09 am
  #2  
ISTFlyer
 
Join Date: Nov 2018
Location: Istanbul, Turkey
Programs: TK M&S Elite Plus, QRPC Platinum, BAEC Silver, PC Bolbol, All Silv, HH Blue, Bonvoy, BW Rewards
Posts: 5,679
American Airlines' change policies are better than British Airways'.
However, if you book through BA, you would have the opportunity to upgrade your flights with POUG or AUP for the return leg with BA.
For your flight from ORD, if you're seeking for a AA paid upgrade, it's better that you purchase your ticket with AA.

These were what came to my mind.
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