What Is An Interline Agreement Between Airlines

An interline flight is an agreement between airlines to coordinate passengers with an itinerary that uses multiple airlines without having to check in again or handle their baggage mid-check-in. Codeshare agreements are cases where airlines operate flights on behalf of another airline using their flight code. For example, a ticket that you purchased from Finnair but is operated on a British Airways aircraft by British Airways. Interline agreements are the most basic types of agreements you can have between airlines. An interline agreement is simply a commercial agreement between airlines to treat passengers when they travel with multiple airlines on the same route. This allows passengers to check their luggage to their final destination, check in at their destination, possibly be booked with another airline in case of irregular operations, etc. Interline agreements were designed to provide convenience to customers who could only reach their destination by connecting with two different airlines. The agreements apply to fares for which both airlines agree to publish a tariff from the airport of departure to the final destination and then distribute the revenue internally between them. The customer would not have to pay two fares depending on each airline`s flight and could get a ticket with two flight segments. The agreement allows each airline to accept the other`s ticket and covers baggage transfers and liability. Often, freight shipments are included in agreements.

International and domestic airlines traditionally participate in agreements. Many low-cost carriers do not participate or have limited agreements. If there is no interline ticketing agreement, two separate tickets must be issued and passengers must collect their luggage and bring it to the connecting airline for check-in. Itineraries with such interline connections are riskier for travelers as the second airline may not be aware of delays or problems with the flight on arrival and may be less likely to allow a free rebooking if the connection is lost. There may also be a problem if the luggage is lost and the traveler wants it sent to them later. Note that airlines typically form joint ventures between certain regions, which is why this is different from a full merger. For example, American has a transatlantic joint venture with British Airways, Finnair and Iberia, while they also have a trans-Pacific joint venture with Japan Airlines. The idea is that this is beneficial for both airlines. I don`t think either airline will get a big discount if you decide to book a codeshare flight instead of directly with the other airline (there may be a small discount), but the main motivation is to boost the business of both airlines by increasing the number of flights that passengers have access to.