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July 9, 2025
Airline Codeshare Partnerships and What You Should Know
I believe airline codeshare agreements are one of the least understood aspects of commercial aviation today.
What are codeshare agreements?
Codeshare agreements, also known as alliance partnerships, exist between airlines usually of different countries so that airlines can collaborate with each other to serve customers on more routes and benefit from traffic they may otherwise not get. For example- if you’re a DFW (Dallas) based customer that always flies American Airlines and you want to fly to Helsinki, Finland, you cannot fly there directly on American Airlines metal because American Airlines does not operate this route. However, because Finnair is a oneworld partner with American Airlines, you can book a direct flight on aa.com from DFW (Dallas) to HEL (Helsinki), which would be operated by Finnair.
Why do you want to book a codeshare flight?
As a passenger, the reason you’d want to book on a codeshare partner is mostly for the reciprocal status perks, although there can be other reasons as well. For example, if you have top tier American Airlines status, you would also have oneworld Emerald status which would unlock perks across many of the oneworld partners, such as Finnair. These perks can be everything from partner lounge access to mileage earning, to priority boarding & first class upgrades, and more.
While there are many different elements to these alliances, below I am just going to touch on what I believe are the most important aspects to have a brief understanding of, which will hopefully make your travel experiences more seamless.
The Big 3 Alliances
- oneworld (13 members, such as American, British Airways, Qatar Airways, Finnair, Cathay Pacific, and more)
- SkyTeam (19 members, such as Delta, Air France, Aeromexico, Korean Air, Virgin Atlantic, and more)
- Star Alliance (25 members, such as United, Air Canada, Lufthansa, Turkish, Asiana, and more)
Almost every airline in the world is a part of one of these three alliances. They have been around since the late 90’s/early 2000’s and have mostly encompassed the same group of airlines throughout, although there have been changes here and there.
Booking seats on a codeshare partner
In my personal travel, I have found the seat element of booking codeshare partners to be the single most frustrating one, and is the one that influences whether I book a codeshare partner more than anything. Furthermore, the main problem with booking a flight operated by a different airline than the one who’s website you’re searching on is that you often cannot select seats. While these airline partnerships can often offer great benefits, I find that the technology integration between them is often lackluster. For example, if you are booking a flight on aa.com from ORD (Chicago) to MAD (Madrid), you may just find yourself booking a flight operated by Iberia, which is Spain’s flag carrier and a oneworld alliance partner with American Airlines. Iberia is known to be a stickler with their seat map and does not open it to customers booking on aa.com. Because of this, I would personally rather forgo any American Airlines benefits I might get from booking on aa.com and just book with Iberia directly. However, more often than not, if you’re flying a codeshare route you’re probably going to be flying multiple different airlines on the same trip. An example of this would be if you’re looking to go from DEN (Denver) to HKG (Hong Kong) on Delta. In this instance, you might fly DEN (Denver) to SEA (Seattle) or SLC (Salt Lake City) on Delta metal and then the rest of the route on Korean Air. When I am booking trips like this, I will usually try to look for the alliance that offers the fastest itinerary, and then book it on whichever airline’s website I care most about seat selection. For example, SLC (Salt Lake City) to HKG (Hong Kong) is a much longer flight leg than DEN (Denver) to SLC (Salt Lake City), thus I’d rather book this trip on Korean Air directly than Delta so that I have control over the seats for the longer leg(s).
It’s important to note that each airline handles their partnerships with other airlines differently, and some are better than others. In my experience, I have found that the SkyTeam alliance partners offer a better seat booking experience on each other’s metal compared to oneworld and Star Alliance. For example, you can select seats on Virgin Atlantic metal while booking through delta.com.
While there are many factors to consider when booking a codeshare partner directly from a US airline’s website, I personally find this to be the most important factor. Others may include: convenience, comfort level with international airlines, and your specific itinerary. Hopefully you found this article helpful and if you ever have questions about booking a trip like this, reach out to us at support@theskykey.com. We LOVE travel and we typically respond lighting fast 🙂.
Does Sky Key work on codeshare flights?
If you book your codeshare flight through any of the major US airlines, Sky Key will work as normal (for example, if you login to aa.com and book a flight on Finnair). If the price of your flight drops, Sky Key will automatically get you savings (in the form of money, points, or future travel credit) while keeping you on the same flight/seats.
– Jacob Goldberg. Co-Founder @ Sky Key