Originally Posted by IntlSalesGuy

I've just learned the hard way that ExpertFlyer availability ("I" fare class) does not always equal the # of upgradeable seats. I was in the process of trying to upgrade my family of 4 from TPE-SEA. EF said there were 4 "I" seats open, so I went ahead and bought 4 "B" fare tickets and tried to upgrade. Eva says there are only 3 seats available, claiming they fall under "Z" fare class. EF still shows the 4 "I" seats open, so it seems Eva has their own inventory to pull from. Best thing to do is call Eva and confirm what is available. It is possible something might open up when you get closer to the flight. You can't waitlist for this type of upgrade, so you just have to keep checking up until 24 hours before the flight.