Originally Posted by
anabolism
My reading of the fare rules is that before departure, voluntary changes to the inbound, with no changes to the outbound, are permitted and are repriced using historical fares as of the previous date of ticketing:
(Emphasis added)
I haven't tried it, but as I read it, one should be allowed to change the return portion without repricing at current fares.
AA told me that the first fare component is CMN-MAD so, before departure, as long as that sector isn't changed, voluntary changes elsewhere are at historical fares. This is how I was able to change LHR-MAD to BA when I haven't yet commenced travel.