What is an interline agreement?

An Interline Agreement is the recognition of one carrier’s transportation documents (airline tickets) by another. In most cases, airlines supplement these agreements with special fare agreements.

For an airline, the benefit of an interline agreement is obvious: through partner flights, the main goal is achieved — attracting passengers with a wider route network.

For the passenger, the main benefit of an interline agreement is the issuance of a single ticket. Let’s say your local airline doesn’t have a flight that can take you to the desired city. Previously, you would have had to first buy a ticket on Kupi.com to an intermediate point, then go to another airline and buy a ticket on Kupi.com for another flight. Thanks to interline, you can buy a single ticket, no matter how many airlines are involved in the transportation. When transferring at an intermediate point, you simply present your ticket, or your passport if it’s an electronic ticket.

Another advantage is an attractive pricing policy. Such a flight is almost always cheaper than buying two separate tickets from point A to point B and from point B to a destination, thanks to special fares that airlines provide for their flight segments.

Interline agreements allow passengers to take advantage of the most convenient connections with flights of different airlines participating in the agreement. They also allow passengers to receive their luggage at the final destination without intermediate check-in — this is known as through baggage check.

Unlike codesharing, interline is not a joint operation of a flight, but simply the recognition of airline tickets issued by another airline; miles and bonus points are not accrued for such flights. An interline agreement gives the airline—a party to the contract—the right to issue tickets for a partner’s flights. For example, if you need to buy a flight ticket on Kupi.com to New York departing from London, you can buy a ticket on Kupi.com for a partner airline’s flight, such as British Airways, directly through another carrier participating in the agreement.

Passengers should remember that the airline that actually operated the flight is responsible for all inconveniences caused during the flight. If luggage was damaged, or a flight was canceled or delayed, all claims are made only to the operating carrier.