Airline alliances explained: Star Alliance, oneworld and SkyTeam

An airline alliance is a group of airlines that agree to work together. For you, that means one frequent flyer account can earn and spend miles on many airlines, and elite status in one program comes with benefits on partner flights.

The three global alliances

There are three major airline alliances:

• Star Alliance, the largest by number of member airlines.
• oneworld, which includes several major US and international carriers.
• SkyTeam, with members across North America, Europe and Asia.

Membership changes from time to time, so check each alliance's official website for the current list before you plan around a specific airline.

How alliances help you earn miles

When you fly an alliance partner, you can usually credit that flight to your preferred program in the same alliance. That lets you build one useful balance instead of scattering miles across programs you'll never use.

How many miles you earn on a partner flight depends on your program's partner earning chart and the fare class you booked. Cheaper fares sometimes earn less, or nothing at all, so check before you fly.

How alliances help you redeem miles

This is where alliances really pay off. Your miles can often book award seats on partner airlines, which means:

• more routes, including places your own airline doesn't fly
• more chances to find award seats on busy dates
• sometimes, lower award prices than the operating airline charges its own members

Partner awards usually have to be booked by phone or through your program's website, and not every partner seat that's for sale is open to partners. For a full walkthrough, start with how airline miles work.

Elite status across an alliance

Each alliance has its own status tiers that map to member programs:

Top-tier alliance status usually brings perks like lounge access, priority check-in and priority boarding on partner flights. The exact benefits vary by airline, so read the details for the carrier you're flying.

Partners outside the alliances

Some airlines don't belong to any alliance but still have useful partnerships. Others have deep partnerships with specific airlines on top of their alliance membership. These can be some of the best ways to use miles, so don't ignore them.

Bottom line

Pick a program in the alliance you fly most, credit partner flights there, and learn which partners your miles can book. Alliances turn one airline's miles into access to much of the world.