Code sharing

business term used in the airline industry for a procedure whereby one airline operates a service using its own flight number, e.g. XX123 and one or more other airlines, in agreement with airline XX, apply their own "code share" flight number to this operation. Most if not all major airlines nowadays have partnerships with other airlines, so called airline alliances. Code sharing is a major reason to start such a partnership.

The term 'code' refers to the flight number that is used in Computerized reservation systems (CRS) also often do not discriminate between direct flights and code sharing flights and present both before options that involve several isolate stretches run by different companies.

Criticism has been levelled against code sharing by consumer organisations and national departments of trade since it is claimed it is confusing and not transparent to passengers but without any success in changing the situation so far.

Code sharing agreements between airlines and rail lines

There are also code sharing agreements between airlines and rail lines. They involve some integration of both types of transport, e.g. in finding out the fastest connection, allowing exchange between an air ticket and a train ticket, or a step further, the air ticket being valid on the train, etc. See also list of IATA-indexed train stations.