There are also codeshare agreements between airlines and railways, officially known as air-rail alliances, often marketed as “Rail & Fly” due to the popularity of Deutsche Bahn`s codeshare with many airlines.  They imply a certain integration of the two modes of transport, e.B. in the search for the fastest connection and the possibility of transfer between the plane and the train with a single ticket. This allows passengers to book an entire trip in one go, often at a discounted price compared to separate tickets. Connecting transaction: A connecting transaction is an agreement where an airline has entered into a codeshare agreement with another airline that does not operate in the same area, but offers connections with other flights. For example, British Airways sells tickets from London to Chicago. However, the entire flight is not operated by them. In most cases, British Airways transports passengers from London to New York. From New York, a connecting partner brings passengers to Chicago. The term “code” refers to the identifier used in a flight plan, usually the two-digit IATA airline code and flight number. Thus, XX224 (flight number 224 of the airline XX) can also be sold by the airline YY as YY568 and by ZZ as ZZ9876. The airlines YY and ZZ are referred to in this case as “marketing airlines” (sometimes abbreviated MKT CXR for “marketing carriers”). Much of the competition in the aviation industry revolves around ticket sales strategies (also known as “seat reservation”) (revenue management, variable pricing, and geo-marketing).
Consumer organisations and national commercial services criticise code-sharing, saying it is confusing and not transparent to passengers.  Simply put, codeshare allows airlines to sell tickets to destinations they do not fly to. These agreements allow airlines to offer many flights without additional equipment, resources and costs. Codeshare also offers passengers a wide range of flights. It also makes booking, check-in, baggage handling and travel more convenient. In addition, the coordinated schedules ensure that you have enough time for all your connections. There`s a lot to like about codeshare and interline flights. I hope this guide has helped you understand the importance of codeshare/line spacing agreements to make aviation even more connected. But there are a few pitfalls to booking a codeshare itinerary.