Originally Posted by
JDiver
Do you have a fully changeable Flight? If not, a human has to calculate the change fee and any difference between what you paid for the original flight and any difference that might be due for the new flight.
That's not really true. There are cases (e.g. some simple domestic roundtrips) where AA.com can calculate and process changes to itineraries without involving a human. I've done this a few times myself and I never purchase fully refundable fares. It will show you the fare difference and change fee before you make the change.
Many other times AA.com can't do this. I'm not sure the rhyme or reason behind which trips it can change and which it can't, but in my experience international trips and/or trips with segments on partner carriers or codeshares can't be changed online.