Originally Posted by
hans
I should know this but if seats show in R (R>0), can you use a GPU to upgrade even if you're not buying a seat in a "W" and above fare class?
No, if your ticket class is below W, the GPU button will be greyed out on the reservations upgrade page. GPU are fare restricted to W and above. You can upgrade a ticket below W with miles and copay $$.
GPU are not fare restricted if the PNR is fully domestic/RPU eligible.