An airline decides on the routes it wants to fly depending on a number of considerations. Quite naturally, it is not possible for any airline, howsoever big it may be, to operate flights on all sectors and especially on those routes which are not having much of demand at present. For this reason, the airlines enter into what are commonly called as the code-share agreements, with one another. These agreements enable the customers to buy the air tickets from one airline, for a route on which the ticket-issuing airline does not operate its own flights but one of its alliance or code-share partner does operate flights. So, you buy the air tickets from one airline but it is the other airline which actually takes you to your destination.
The airlines enter into these agreements with each other so that the routes operated by one airline, called operating carrier, are used by the other airline, called the marketing carrier, for flying their passengers. So, while you might be booking the flight tickets on one airline, you would be required to go the counter of a different airline at the airport for catching the flight. While the air tickets issued are from the airline on which you did the booking, it is the other airline which does the ground handling and flies you to your destination. In a nutshell, the marketing carrier is, at best, a booking airline only.
The code-share agreements are beneficial to both airlines as well as to passengers. Both the airlines have greater access to the newer destinations and can book the flight tickets on routes not served by them. It obviates the need of operating more flights or increasing the frequency of flights to the different destinations by any one airline. While the marketing airline would save on the operating costs, the operating carrier would be able to get more customers. The airlines can also have improved occupancy rates of their flights. This is particularly helpful to the relatively lesser known brands of airlines as the passengers get to experience the airline by flying with it.
For the passengers, the code-share agreements give them a chance to book the air tickets with a single flight code even if they have to fly on connecting flights. There is a no need for making separate bookings under different codes. While catching a connecting flight under a code-share flight ticket, the second airline cannot deny boarding of the plane if there is delay from the first one. So, the code-share agreements are a win-win situation for both airlines and also for the passengers.
The author is employed with leading online travel agency of India which offers air tickets, hotels and holiday packages to the customers. You can look for and book the flight tickets for your travel on this portal.