I've found this recently for C class availability LHR/JFK. Expertflyer says C6 but when I phone BA, they say C0. Also vice versa. Presumably it's looking at US inventory? Anyone know?
It is indeed. It takes the info from Sabre. If you find that EF shows availability but reservations says no, then a call to +1 1800 airways and speaking to the US reservations should allow you to get the inventory
Dave