Codeshare flights For example, you can purchase a seat on a plane under one airline, but it will actually be a seat on a plane of a different airline, which shares the same flight number or code. Codeshares often happen within alliances, such as OneWorld or SkyTeam, but not always.

Yes, airlines share flight numbers through a business arrangement known as a "Codeshare Agreement." This allows one airline (the "operating carrier") to fly the actual aircraft while one or more partner airlines (the "marketing carriers") sell seats on that same flight under their own airline designator and unique flight number. For example, a flight from London to New York might be physically operated by British Airways (BA117), but it could also be sold by American Airlines as AA6164 and by Iberia as IB4695. This is a key feature of major global alliances like Star Alliance, SkyTeam, and oneworld, as it allows airlines to offer a much wider network of destinations without the expense of flying their own planes on every route. For passengers, this means you can book a multi-leg journey through a single airline's website, even if different carriers are flying the individual segments, often resulting in synchronized baggage handling and smoother connections at hub airports.