The section 399.87 requirement that U.S. and foreign carriers apply the baggage allowances and fees that apply at the beginning of a passenger’s itinerary throughout his or her entire itinerary does not prohibit carriers from using the “most significant carrier” (MSC) methodology for international flights set forth in IATA Resolution 302, as conditioned by DOT Order 2009-9-20, to determine which carrier’s baggage rules apply to international itineraries. However, as is the case with all IATA resolutions, Resolution 302 is not binding on IATA or non-IATA carriers.

Example 4 (international interline): Passenger books a ticket from Dallas, changing planes in New York, with a stopover in Amsterdam, continuing to Madrid, and returning to Dallas via Amsterdam and New York, with no stopovers on the return. The ticket indicates the operating carrier’s code and flight number for each segment (there are no code-shares).

Dallas-New York segment is operated by Carrier A (outbound and return)

New York – Amsterdam segment is operated by Carrier B (outbound and return)

Amsterdam-Madrid segment is operated by Carrier C (outbound and return)

The first carrier (Carrier A), has the option to use the MSC methodology to determine which carrier’s baggage allowance and fees to apply. If Carrier A chooses to apply the MSC methodology, as conditioned, Carrier B’s baggage allowances and fees would apply for the entire itinerary. The MSC in this example would be Carrier B, the carrier operating across the Atlantic. Alternatively, Carrier A could choose to apply its own, and not the MSC, baggage allowances and fees, and those would apply for the entire itinerary. The Enforcement Office reminds carriers that section 399.87 does not relieve carriers of their obligations under tariff filing rules and regulations. Therefore, in determining what fee applies at the beginning of a journey, a carrier must be mindful of all rules and regulations that cover that passenger’s ticketed journey.