In the previous post, I talked about connecting flights. I dived into which regions, countries, airlines, and cities are optimal to connect in when traveling between two points.
While it would be straightforward to fly one airline for the entirety of the journey, no airline serves all the possible city combinations. So, there will be cases where you have to combine multiple airlines for your journey. There are many different ways in which this works in practice, so I’ll cover the most common cases.
Case 1: Codeshare flights
A codeshare agreement is a partnership between airlines that allows one airline to sell seats on a flight operated by another airline under its own flight number. This enhances connectivity, expands route options for passengers, and enables seamless booking and baggage transfers across multiple carriers.
Say you want to fly from Hong Kong to Miami in the United States. Searching for random dates on Cathay Pacific, the airline of Hong Kong, returns the following flight options, amongst others.
Cathay Pacific does not fly to Miami but they do fly to other U.S cities, including Los Angeles (LAX) and New York-JFK. The flight search above on Cathay Pacific website shows connecting flight to Miami from LAX and JFK operated by American Airlines but with Cathay Pacific (CX) flight number.
Now, Cathay Pacific could technically have a codeshare agreement with any other U.S. based airlines like Delta, United, or JetBlue. So why only American Airlines? Enter, airline alliances.
Case 2: Airline Alliance
Airline alliances are global networks of airlines that coordinate schedules, share resources, and most importantly for frequent flyers like myself, offer reciprocal benefits like mileage earning, elite perks, lounge access, and seamless connections.
Taking the previous example, Cathay Pacific and American Airlines both belong to oneworld alliance (more on this later). Today, there are three major airline alliances.
Star Alliance
Star Alliance was founded in 1997 by Air Canada, Lufthansa, Scandinavian Airlines (which left Star Alliance in 2024), Thai Airways, and United Airlines. It is the largest airline alliance with the following 25 airlines (as of February 2025).
I’ve broken down the member list into regions, with airlines I’ve flown in bold. I’ve flown 16 of 25 member airlines as of February 2025, so I’m still missing a few! In fact, I have upcoming flight on South African Airways, crossing another one off the list.
| Asia Pacific | Americas | Europe | Middle East/Africa |
|---|---|---|---|
| Air China | Air Canada | Aegean | Egyptair |
| Air India | avianca | Austrian | Ethiopian Airlines |
| Air New Zealand | Copa Airlines | Brussels Airlines | South African Airways |
| ANA | United Airlines | Croatia Airlines | |
| Asiana Airlines | ITA Airways (Future Member) | ||
| Eva Air | LOT Polish Airlines | ||
| Shenzhen Airlines | Lufthansa | ||
| Singapore Airlines | Swiss | ||
| Thai Airways International | TAP Air Portugal | ||
| Turkish Airlines |
SkyTeam member ITA Airways is moving over to Star Alliance, with Lufthansa taking a stake in ITA Airways. The exit process of ITA Airways from SkyTeam alliance is slated to complete by April 30, 2025.
Evidently, Star Alliance has strong coverage in Asia, Europe, North and Central America, and Africa.
oneworld
oneworld was founded in 1999 by American Airlines, British Airways, Cathay Pacific, and Qantas.
Based in Japan, I regularly use a Japan Airlines credit card. So without being too biased, oneworld is my preferred alliance at the moment. Cathay Pacific has great lounges and good connectivity within Asia. Meanwhile, Qatar Airways with their award winning Qsuite business class is excellent for flights to Europe, the Middle East, and Africa.
Again, airlines I’ve flown are in bold. So far, I’ve flown 7 of 13 member airlines as of February 2025, with an upcoming flight on Finnair, crossing another one off the list.
| Asia Pacific | Americas | Europe | Middle East/Africa |
|---|---|---|---|
| Cathay Pacific | Alaska Airlines | British Airways | Qatar Airways |
| Japan Airlines | American Airlines | Finnair | Royal Air Maroc |
| Malaysia Airlines | Hawaiian Airlines (Future Member) | Iberia | Royal Jordanian |
| Qantas | Oman Air (Future Member) | ||
| SriLankan Airlines | |||
| Fiji Airways (oneworld connect) |
3 airlines are expected to become full oneworld alliance members in the coming years. Fiji Airways has been a oneworld connect member since 2018, and expected to become a full member around March/April 2025. Oman Air have announced June 30th, 2025 as their joining date to oneworld alliance. Following the buyout of Hawaiian Airlines by Alaska Airlines, Hawaiian Airlines is next in line to join oneworld alliance, likely in 2026.
oneworld has strong presence in Asia and in Middle East. However, its European coverage is somewhat scattered, with major hubs in the UK (British Airways), Finland (Finnair), and Spain (Iberia). Hence, connectivity within Eastern Europe is lacking, for example. South America is also a weak spot.
SkyTeam
SkyTeam was founded in June 2000 by Aeroméxico, Air France, Delta Air Lines, and Korean Air, making it the last of the three major alliances to be formed. Despite this, it is the second largest alliance, surpassing oneworld.
I’ve again broke down the member list into regions, with Aeroflot being absent from the list above as its membership is currently suspended. Again, airlines I’ve flown are in bold. Only 3 of 18 as of February 2025, with upcoming flight booked on Scandinavian Airlines (SAS).
| Asia Pacific | Americas | Europe | Middle East/Africa |
|---|---|---|---|
| China Airlines | Aerolíneas Argentinas | Aeroflot (Suspended) | Kenya Airways |
| China Eastern | Aeromexico | Air Europa | Middle East Airlines (MEA) |
| Garuda Indonesia | Delta Air Lines | Air France | Saudia |
| Korean Air | KLM Royal Dutch Airlines | ||
| Vietnam Airlines | Scandinavian Airlines (SAS) | ||
| XiamenAir | TAROM | ||
| Virgin Atlantic |
SkyTeam has a solid presence in North America, Asia, and Europe. However, its Middle Eastern network is weaker, lacking a major Gulf carrier.
Case 3: Joint Venture (JV)
While airline alliances have many benefits, not all alliance member airlines actively cooperate on all routes. Airlines strategically choose partners that complement their networks and strengthen their market position, even outside their alliance.
Examples include partnerships like Qantas and Emirates or Japan Airlines and Garuda Indonesia, where airlines collaborate beyond alliance boundaries.
A Joint Venture (JV) represents a deeper partnership, where airlines agree to share revenue on specific routes and coordinate schedules to optimize operations. These agreements require extensive negotiations and often government approval, as they can impact competition by closely aligning the partner airlines.
In recent years, airlines within alliances have also embarked on JVs to further streamline their operations.
For example, in the oneworld alliance, several JVs exist among its member airlines, further strengthening the alliance and enhancing connectivity:
- Transatlantic JV between American Airlines, British Airways, Iberia, and Finnair, coordinating flights and revenue sharing on routes between North America and Europe.
- Transpacific JV between American Airlines and Japan Airlines, optimizing scheduling and revenue sharing on routes between Asia and North America.
- Another JV between British Airways, Iberia, Finnair, and Japan Airlines, covering Europe-Asia routes.
Shown above are the flight search results from the British Airways website for flights from London Heathrow to New York on a selected date. You can observe how American Airlines and British Airways offer different departure times for the same route, and notably, the prices for each class remain the same across both airlines.
Given their transatlantic JV, there’s no incentive for either American Airlines or British Airways to undercut the other in order to gain more passengers, as they share the revenue from these flights.
Conclusion
Now that you know how airline codeshares, alliances, and joint ventures work, you’ll have a better understanding of how different flight combinations show up when you search for your next trip. These partnerships help airlines offer more options, better connectivity, and enhanced benefits.
Knowing these facts can help you make more informed choices when booking your next flight, allowing you to find the best routes, maximize your benefits, and make the most of your travel and flying experience!