Originally Posted by wickedlfe

Hey Randy - usually the Y or B fare is the "Eco Flex" one. You can check by clicking the fare you want and the the Fare Basis/Details button on the right side. After checking on United's website for Business Class Award availability on EVA, I would also follow up with a call to EVA to confirm that they indeed have Z class available on the particular flight you want to book. Having said all that, I will tell you that in my experience it is still not a 100% success even if both those criteria are met. The only way to absolutely know is to buy the ticket and try the upgrade. If it doesn't work, apply for a refund of the ticket on Eva's website within 24 hours and you'll get a full refund. There's a pop up that says it could take 2 months for the refund to go back on your credit card, but in my experience its usually 7-10 days.

I believe "I" Class is United's coding for business class award. "Z" class is Eva's coding for the limited upgrade-able business class seats. If you talk to United, you should ask for I. If you talk to Eva, you should ask for Z.

I subscribed to ExpertFlyer and was disappointed in the functionality. Even worse was their customer service. I emailed them a few times to ask questions around my search results and they were very rude.

As far as I know, there is not a limit on how early you can upgrade the ticket as long as there is an upgradeable seat to take. The minimal time is 24 hours (I tried to upgrade once the day before and got an error message that upgrades need to be completed before 24 hours before departure).