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What Are Codeshare Flights and How Do They Work?

July 05, 2019
5 min read
What Are Codeshare Flights and How Do They Work?
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You may have checked a departures information screen for your flight and found the correct flight time, destination and departure gate, but the flight number is different to the flight you booked. The two letter prefix may be for a completely different airline, though worry not, that code is just the airline code of the operating airline's partner and your ticket will be valid on their flight.

Why is this? You may be on a codeshare flight.

Codeshares are business arrangements where two or more airlines agree to market and publish a particular flight as part of their own schedule or timetable. Only one carrier actually operates the flight, however the other airlines marketing the flight can all add their own unique flight number to the flight for marketing purposes.

KLM and Delta are a good example of a close and successful codeshare arrangement. Both operate flights hubs at Amsterdam (AMS) airport, with Delta operating flights from there to the US, with KLM operating (some) flights to the US but more-so to other destinations Delta does not operate to. So, for example if you wanted to fly from, say Bristol (BRS) to Seattle (SEA), there are no direct flights. You might know KLM flies from Bristol, while Delta flies from Seattle. But neither carrier flies to both. But codeshares allow you to book a single connecting ticket from Bristol to Seattle on both carriers.

You could either book it:

  • Through with a DL coded, KLM operated flight from Bristol to Amsterdam and then a DL coded, DL operated flight from Amsterdam to Seattle; or
  • Through with a KL coded, KLM operated flight from Bristol to Amsterdam and then a KL coded, DL operated flight from Amsterdam to Seattle.

So what are the advantages of codeshares as a traveler?

  • They allow you to book connections that wouldn't otherwise exist, as a single carrier wouldn't operate the full journey.
  • You will be protected if any delays in one flight cause you to miss subsequent flights.
  • You can usually earn points and miles in the program of the airlines whose code the flights have, even if you might not earn them if booked on the other airlines own code. Codeshares are the secret way to earn Avios on Emirates flights.
  • It allows airlines who are not members of the same alliance to offer seamless connections and other partnership benefits.
  • It reduces confusion for passengers who have a single ticket booked across multiple airlines — they can simply look for their own airlines code on each flight and not have to worry who is actually operating the flights.
  • Where airlines codeshare on the same route (i.e. both airlines fly the route themselves and put their code on other airlines as well) it allows them to market increased frequencies which is attractive to lucrative business travelers.
  • Airlines can also market that they service more destinations where they simply codeshare to a certain destination.
  • If a route an airline only codeshares on does not perform they can simply pull their code off the route, without the huge operational and financial implications of canceling their own route.
(Photo by Katherine Fan/The Points Guy)

But there are some pitfalls of booking a codeshare itinerary.

Most airlines operate vastly different products, especially in premium cabins, so you may be in for a shock if you are expecting to step on to a KLM flight and board to see a Delta crew and cabin awaiting you. Like different products, different airlines can have differing baggage policies and other ancillary fees. Ideally the one allowance would apply to all flights but you may find yourself in a confusing argument with a check-in agent if they are expecting to be allowed to check more luggage than the operating airlines thinks they should!

Some airlines may sell a premium economy codeshare but if one or more of the operating carriers does not offer premium economy you may be automatically seated in economy with no warning or compensation.

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This can also happen for first and business class, though it is less common as airlines would be very brave attempting to sell a first class itinerary where major parts of the itinerary are in business class, unless they made this very clear to the passengers at the time of booking.

Delta's all-new Delta One seat, featured on refurbished Boeing 767-400 aircraft (Rendering courtesy of Delta Air Lines)

Finally, how do you know if you're on a codeshare flight? When booking this should be disclosed to you — for flights to and from the US, it is a US Department of Transport regulation that airlines must advise their passengers if they will be on a codeshare service. Most airlines will sell the ticket as 'Flight XX123, operated by XYZ'