Join Date: Oct 2007
Location: LONDON
Programs: CX DM, BA G4L, QR PLT, EK PLT, Hyatt CC, HH DM, SQ SLTRE, BonvoyTit, UK SL, VS Wings, UA, DL, AA
Posts: 1,756
The fare difference is calculated at the airport based on a HALF R/T HALF R/T R/E fare and then difference is charged and upgrade done.
Instant upgrades are a great feature of the MPC/AM programs and I am glad that they have the sense to do everything quickly at the airport - only wish BA could learn from this