Originally Posted by LHR/MEL/Europe FF

Voluntary change of class was not allowed for some time in the closing stages of USDM unless you did exactly as they suggest - redeposit and rebook the entire itinerary.

While this most commonly came up with pax who might have paid F for the whole ticket, but only had availability in J for one sector at time of booking... I suppose it equally would apply to a requested downgrade.

For a while you could play agent roulette and hope one would make the change without needing to cancel... but by the end it was almost uniform. I tried with four agents in September last year and all of them gave the same line.