Originally Posted by
Kacee
My experience is with UA, where they will give you both the fare difference and fixed cs comp based on the length of the flight. In determining fare difference, there is much play in the system. I've had success telling them what the differential should be, but the airline will generally default to day of departure fares, which of course is highly favorable from the carrier's perspective.
There's a wiki thread in the UA forum which goes into a fair amount of detail. It claims the fare difference is calculated based on the lowest published fare for coach at time of ticket purchase, but I couldn't find anything in UA CoC to back that up.
https://www.flyertalk.com/forum/unit...ation-etc.html
DOT does not define how to calculate fare difference. There is a section in IDB compensation rules about how to determine compensation for "zero fare tickets" like award tickets and uses "
The fare paid by these passengers for purposes of calculating denied boarding compensation shall be the lowest cash, check, or credit card payment charged for a ticket in the same class of service on that flight." But that's not relevant for downgrade compensation.