To be more specific, it's the fare bucket availability that changes all the time (the fare filings themselves don't get updated all that frequently). While AF/KL/DL/VS coordinate on fare filings on TATL routes, they often have different fare bucket availability for the same flights. In case below DL has U bucket outbound and V bucket return. AF also has V bucket return open and same VHW57NMZ fare (but as AF filing instead of DL), but outbound flights have T open and THW47NML fare on outbound. Although there are a number of differences in fare class hierarchies between carriers.





There are cheaper seasonal fares for travel on/after July 11th for $1037 roundtrip. They are NLN87NBX AF fares and TLN87NBX DL fares. Note that AF Economy Light fares will earn DL Skymiles, while DL Basic Economy fares do not (such as the DL fares below even when flying on AF metal).