Originally Posted by SQPPS

The rule is and should be that the baggage allowance that applies is for the highest class of service on your itinerary.

Imagine taking a regional jet with 1 class of service to connect to F from JFK/LHR. AA would be foolish to not offer the 1st Class Allowance.

If the agent has a problem with that then you need to fight for it. Most airlines will honor the highest class of service on the itinerary. In many cases F is now not available in this world b/c its simply not offered or it might be sold out for your first sector. This just happened to me when I flew SIN/DXB/ZRH. DXB ZRH was F but the first sector busienss. I was offered the F class bag allowance without question.

Happned on BA, LX, and numerous others including AA out of PLS. PLS to MIA in Y and MIA/LHR in F.