Just adding another data point that the "Change Flight" worked for me in extending my FFC credit
- I had a large FFC with begin travel date by April 2025, with no personal travel plans until July 2025
- I booked an economy flight (not refundable) for March 1, 2025 for a fare $10 more than my FFC
- I waited 24 hours and then selected "Change Flight" to move my March 1 trip to match the itinerary I wanted for July 2025 (completely different destination city)
- I was only required to pay the increase in fare above my FFC already applied to original flight.
Not sure if I needed all these steps but I was happy it worked. This thread is very confusing and results seem mixed.