hey guys, I posted all the details a year ago in this thread
so to refresh your memory, look here :
https://www.flyertalk.com/forum/29670117-post1187.html

there were very few restrictions for the originally-booked fare, and Premium Eco A fare was not excluded. This is worrisome to know that it is now excluded. But is this really true (I mean could the agent be wrong) ?
because it doesn’t really make sense to me as a A fare is more expensive than some upgradable Eco fares
We should investigate whether they changed the rules I described in the linked post. I wouldn’t be surprised if there have been a few changes (more restrictions) based on my recent experience :
- last year, I used my 2 upgrade certificates on a September round trip CDG-BOS. I called the TA and everything was done very easily booking me in the cheapest Eligible Y fare (I don’t know which one) and instant upgrade. I paid around €650.
- last month, I wanted to use the 2019 certificates also for a US trip next summer. I looked online first and saw that I could buy it in Eco for about €700 (which is not too bad for the summer). Of course, I wasn’t sure that, at that price, it was in an eligible fare for the upgrade, so I call the TA. They said that the cheapest Y fare they have to book me in for the upgrade was around €1250. which is a very significant difference.
So I finally didn’t take it and used miles instead to book the ticket in J...for about 173K and something like €530 in taxes