Originally Posted by
JJeffrey
No no. J is full fare business class, U is award space (sAAver business), and C can be upgrade space or a revenue business class fare bucket.
C space is what you need for an SWU upgrade, BUT you must search ExpertFlyer using the "Awards and Upgrades" section to see the correct C space. If you search using the "Flight Availability" function then any C space you see doesn't correlate to upgrades. I'd be shocked if an AA metal flight to SYD is actually C7.
Exactly this. Just to further clarify, Expert Flyer upgrade inventory is only accurate on non-stop/direct flights. When doing a search, use the "Awards and upgrades" query and set "Connection preference" to "Direct/non-stop only" and check the "Exclude codeshares" box. Only then will you be certain that the results you see are upgrade inventory.