Originally Posted by
Superguy
Problem is, codeshares have been problematic for upgrades under the current system. If you have a US codeshare operated by AA or vice versa, it's unclear how the upgrade would apply.
I think we can agree it SHOULD work. Whether it actually would is another story.
On the web pages explaining the transition, it said you should still buy tickets from the operating carrier until all flights are under a single reservation system. Any codeshare AA/US situation will require the 24-hour check-in only upgrade process (and good luck with that). I have one coming up, unfortunately, but the AA price was quite a bit less than the US price.
For 500 mile upgrades, this is the text:
If you’re booked on a codeshare flight, you’ll only be eligible to upgrade when you check in, and as always, upgrades are based on availability.