Airline Partnerships Explained: Alliances, Codeshares, and More

TL;DR

• Not every airline partnership means the same thing; alliances, codeshares, interline agreements, and joint ventures all work differently.
• The three global alliances, Star Alliance (26 members), oneworld (15), and SkyTeam (18), offer the deepest reciprocal benefits, including shared elite status and mile redemption.
• A codeshare lets one airline sell seats on another’s flight, but it doesn’t automatically mean you’ll earn miles or get elite perks on that ticket.
• Joint ventures go further still, letting airlines coordinate pricing and schedules on specific routes, as seen with Delta, Air France-KLM, and Virgin Atlantic.
• Not every airline partnership survives. American and JetBlue’s Northeast Alliance was dismantled by regulators in 2023, while United and JetBlue’s newer Blue Sky partnership is still standing in 2026.

Airline partnerships come in more forms than most travelers realize, and the differences matter more than they seem. Two airlines can be “partners” in at least five distinct ways, and each one changes what you can actually do with your miles. This guide breaks down every type of airline partnership you’ll run into, with current, real examples of each, so you know exactly what a given relationship means before you try to book with it.

What Counts as an Airline Partnership

Not all airline partnerships sit at the same depth. Some involve full reciprocal loyalty benefits, while others are little more than a shared booking system.

• Global alliance membership, the deepest and broadest form, covering Star Alliance, oneworld, and SkyTeam.
• Codeshare agreements, where one airline sells seats on a partner’s flight under its own flight number.
• Interline agreements, which allow through-checked bags and connecting itineraries without necessarily sharing loyalty benefits.
• Joint ventures, also called joint business agreements, where airlines coordinate pricing and scheduling on specific routes.
• Standalone bilateral partnerships, direct deals between two airlines that sit entirely outside any global alliance.

Rather than learning to spot each type manually, you can search award flights across nearly every one of these partnership types at once on Flightpoints.

Global Alliances: The Deepest Airline Partnership

A global alliance is the strongest form of airline partnership available, since membership brings mutual elite recognition, shared lounge access, and the ability to earn and redeem miles across every member airline.

• Star Alliance is the largest and most global, recently gaining ITA Airways in April 2026.
• oneworld is the smallest by member count but covers the U.S., U.K., and Australia unusually well.
• SkyTeam sits in between, with strong coverage in Asia and a growing Scandinavian presence through SAS.

Membership in one of these alliances is what makes an airline partnership feel seamless: your status, your miles, and your booking all move together.

Codeshare Agreements Explained

A codeshare is one of the most common but least understood airline partnerships. It simply means one airline sells tickets on a flight that’s actually operated by a different airline, using its own flight number.

• The flight itself is only ever operated by one airline, no matter how many flight numbers are attached to it.
• Codeshares can exist between alliance partners, but they’re just as common between airlines with no alliance ties at all.
• Earning miles or elite credit on a codeshare flight depends entirely on the specific agreement; it isn’t automatic.
• Always check which airline is the operating carrier before assuming your miles or status will count as expected.

Interline Agreements Explained

An interline agreement is a lighter-touch airline partnership that mainly deals with logistics rather than loyalty benefits. It lets two airlines sell a single ticket covering flights on both carriers.

• Bags can typically be checked through to your final destination, even across separate airlines.
• If one flight is delayed and causes a missed connection, the airlines involved will usually rebook you without extra cost.
• Interline agreements don’t automatically include reciprocal mile earning or elite status recognition.
• Many interline deals exist between airlines in completely different alliances, or even airlines with no alliance at all.

Joint Ventures: When Airline Partnerships Get Serious

A joint venture, sometimes called a joint business agreement, is the most commercially integrated airline partnership short of an outright merger. Airlines in a joint venture can coordinate pricing, schedules, and revenue sharing on specific routes, usually with antitrust immunity from regulators.

• These deals require government approval, and that approval isn’t guaranteed or permanent.
• Airlines in the same joint venture will often show matching prices on overlapping routes.
• A joint venture is deeper than a standard alliance relationship, since it involves actual coordination on commercial terms.
• Not every alliance member is part of every joint venture within that alliance.

Curious whether a specific route benefits from one of these deeper partnerships? Search live award availability on Flightpoints and compare pricing across the airlines involved.

Standalone Partnerships Outside the Alliances

Some of the most useful airline partnerships for points collectors exist entirely outside Star Alliance, oneworld, and SkyTeam. These bilateral deals let two airlines share loyalty benefits without either one joining the other’s alliance.

• Alaska Airlines’ Atmos Rewards program keeps standalone partnerships with airlines like Icelandair, Korean Air, Condor, and Hainan Airlines, alongside its full oneworld membership.
• United and JetBlue’s Blue Sky partnership launched reciprocal mile earning and redemption in October 2025, followed by reciprocal elite perks like priority boarding and free checked bags in May 2026.
• Delta and WestJet maintain a deep codeshare and reciprocal elite benefits relationship, and Delta took a 15% equity stake in WestJet in 2025, though the two airlines abandoned a full antitrust-immunized joint venture back in 2020.

None of these three examples involve shared alliance membership, which shows that a strong airline partnership doesn’t require one.

When Airline Partnerships Fall Apart

Airline partnerships aren’t permanent, and one recent case shows exactly how quickly a deep relationship can unravel. American Airlines and JetBlue’s Northeast Alliance is the clearest example.

• The Northeast Alliance combined operations at Boston and New York airports starting in 2020, with full reciprocal loyalty benefits.
• A federal judge struck it down in 2023 on antitrust grounds, and JetBlue began winding it down that July.
• The Supreme Court declined to hear American’s appeal in 2025, leaving the alliance permanently dismantled.
• In February 2026, JetBlue agreed to pay American Airlines $100 million in damages tied to the collapse.

This kind of breakdown is a useful reminder: don’t build a long-term points strategy around a single airline partnership without a backup plan.

Why Airline Partnerships Matter for Your Miles

Understanding the type of airline partnership behind a booking changes what you should expect from it. A codeshare won’t guarantee elite perks the way alliance membership does, and a standalone deal like Blue Sky might not extend as far as a full joint venture.

• Before booking, confirm which airline is actually operating your flight.
• Check whether the specific partnership includes mile earning, elite recognition, or both.
• Remember that joint ventures and standalone deals can change or end with little warning.
• Transfer partners tied to credit card points, like Amex Membership Rewards or Chase Ultimate Rewards, often reach further than a single airline partnership alone.

Conclusion

Airline partnerships range from a full global alliance down to a narrow codeshare agreement, and knowing the difference keeps you from assuming benefits that were never actually part of the deal. Alliances offer the most consistency, joint ventures bring the deepest commercial coordination, and standalone partnerships like Blue Sky prove that meaningful airline partnerships can exist entirely outside the traditional alliance structure. Whichever kind you’re relying on, it’s worth double-checking what it actually includes before you book.

FAQs

Q: What is the difference between an airline alliance and a codeshare?
A: An alliance is a full membership relationship covering mile earning, elite status, and lounge access across every member airline. A codeshare is narrower: it just means one airline sells seats on a partner’s flight under its own flight number.

Q: Do all airline partnerships let you earn miles?
A: No. Global alliance membership almost always includes mile earning, but codeshares and interline agreements don’t guarantee it. Always check the specific terms of that airline partnership before assuming your miles will count.

Q: What is a joint venture between airlines?
A: A joint venture, or joint business agreement, lets airlines coordinate pricing and scheduling on specific routes with antitrust immunity from regulators. It’s a deeper commercial relationship than standard alliance membership.

Q: Can two airlines have a strong partnership without sharing an alliance?
A: Yes. United and JetBlue’s Blue Sky partnership and Delta’s relationship with WestJet both operate entirely outside the three global alliances, yet still offer reciprocal mile earning and, in some cases, elite benefits.

Q: Why did American Airlines and JetBlue’s partnership end?
A: Their Northeast Alliance was struck down by a federal judge in 2023 on antitrust grounds. JetBlue wound the partnership down that year, and the Supreme Court left the ruling in place in 2025.

Q: How many airlines are in each global alliance?
A: Star Alliance has 26 member airlines, SkyTeam has 18, and oneworld has 15, as of mid-2026.