The downside of an interline agreement is that passengers cannot collect frequent flyer miles for the entire trip. For example, on the Emirates flight, Skywards miles would only be collected on the Dubai-Mexico part of the flight, not on the continuation of the journey. In all these partnerships, the exact details vary depending on the agreement that will be concluded. I hope this will provide a useful insight into demystifying some of the partnership terminologies often used by airlines around the world. Codeshares are beneficial for airlines because they allow customers to reach new destinations that are not served by their own aircraft, meaning they can offer a wider choice of destinations without going there. It also means that they can focus their services on the goals they already offer, i.e. more frequent services. In addition, airlines automatically transport their luggage to the connecting airport. The agreements also apply to irregular transactions in which customers can be transferred free of charge to other airlines. Other irregularities are damage to luggage, delays or losses if the customer only suffers with the final supplier, regardless of which airline is responsible for the irregularity. Interline, also known as interline and interline ticketing, is a voluntary commercial agreement between different airlines to process passengers traveling on routes requiring multiple flights with multiple airlines.  Such agreements allow passengers to switch from one flight with one airline to another without having to collect or re-check their luggage.
Airlines can also promise a free rebooking if the service is interrupted due to a delay. @Hung Nguyen: Just a word of caution. Although QR has an interline agreement with the UN, most of these agreements only apply if you are travelling with a ticket, but not with separate tickets. There may be exceptions, but I don`t expect to check luggage for separate tickets. These agreements facilitate cooperation between airlines3 The number of multilateral/bilateral agreements to which debtors are parties makes it very difficult to identify each of these agreements, but debtors strive to remedy all interline agreements, whether or not a particular agreement is listed in Annex A. Cargo, baggage and mail between airlines. Codeshare agreements focus on flight plans and aircraft sharing. A codeshare customer can buy a ticket for one airline, but travel with another airline if both have agreed to the relationship. Customers who wish to travel with airlines with codeshare agreements have a wider choice of flights, as the ticket can be used interchangeably by both airlines, subject to fare rules and inventory availability. Because tickets are interchangeable, airlines with codeshare agreements also have an interline agreement. Codeshare agreements usually also offer the accumulation of miles for the bonus program for the customer`s choice program….