Originally Posted by
Ditto
Do you have extra luggage allowance on AS? If so then they made a mistake by allowing you to send them through since even if it was on one ticket, SU luggage allowance would have been the right one to follow.
I do have excess luggage allowances on AS.
I think you're talking about the Most Significant Carrier rules (IATA 302), which don't usually apply to itineraries arriving or departing the USA (US DOT 399.87 -- in general, the baggage rules of the first carrier accepting the luggage apply to the whole itinerary).
Regardless if AS chose to charge me or not, they would be the one responsible for reconciling any interline and/or excess baggage charges with SU under their ticketing & baggage agreement.
(For example, AS MVPG members also can check two bags on AA, and I have used that to check bags for an itinerary with an AA flight connecting to AY.)
I don't see how any airline could expect to charge a passenger for thru-checked bags that are already in transit.
.... but, I'm asking in case anyone has experienced anything similar!