Originally Posted by
f0zzyNUE
bid for upgrade also worked from the cheapo premium economy tickets ("A"-class). however a mileage upgrade or an upgrade via upgrade voucher is only possible from booking class "P".
That’s also my understanding. It’s a shame they’re so restrictive - I have enough miles sitting in my account to upgrade from PE to J, but alas am booked in A class. I called AZ and they confirmed I could only upgrade from P using miles.
If my bid for upgrade doesn’t work I will ask again at check in both in LHR and FCO. Are there any data points about AUPs?