End-on-end combination is a fare construction practice in which separate round-trip fares are linked together at a common connecting point to form one larger itinerary.
Rather than using a single through fare between the starting point and final destination, the journey is divided into multiple fare components that are combined sequentially. Each fare covers a different portion of the trip, but together they create the passenger’s complete routing.
For example, a traveler wants to fly from City A to City C through City B. Instead of purchasing a direct round-trip fare between A and C, the traveler buys one round-trip fare from A to B and another from B to C. In some situations, the total of the two separate fares may be lower than the airline’s published through fare for A–C.