United Airlines' MileagePlus is the world's largest airline loyalty program by disclosed membership, with more than 130 million members, according to a new ranking of the eight biggest schemes. Delta SkyMiles follows with 120 million, and American Airlines' AAdvantage sits at 115 million — though that last figure dates from 2021 and has almost certainly grown since.
The rankings come with a caveat worth remembering: airlines disclose membership numbers on different schedules and with different definitions, so this is a snapshot rather than a like-for-like contest. American's total is five years old, while United's, Delta's and Southwest's are all from 2026. A fresher AAdvantage number could well reshuffle the top three.
Southwest Rapid Rewards is next, at nearly 100 million members as of its second-quarter 2026 results, with new enrollments up 35% year over year. In Europe, IAG's shared Avios currency — used by British Airways, Iberia, Aer Lingus and Vueling — has more than 70 million enrolled members, making it Europe's largest loyalty platform. IAG says it issued 200 billion Avios in 2025 alone.
Further down, LATAM Pass counts around 54 million members (up 9% year over year, though only about 35% were active in the past two years), Lufthansa Group's Miles & More has over 36 million, and Air France-KLM's Flying Blue recently passed 35 million. Notably, only LATAM and Southwest's figures are genuinely recent in the smaller tier — Miles & More's number is its most recent official disclosure, from 2022-era reporting.
What's the takeaway for anyone who collects miles? These programs are no longer about flights alone. Flying Blue members can earn through more than 100 partners including Uber, Booking.com and France's SNCF trains. SkyMiles is deeply intertwined with American Express cards. MileagePlus points never expire and award seats carry no blackout dates. The biggest programs have become everyday spending ecosystems, which means the savviest collectors often earn more miles with a credit card or a hotel stay than in the air.
It also means raw membership counts overstate how many people are actually engaged. LATAM's own filing is refreshingly honest here: only around a third of its 54 million members earned or redeemed anything in the previous two years. If you hold miles in one of these programs, the practical advice is to keep your account active — small earning or redemption activity keeps balances alive and, on programs like LATAM Pass, keeps you counted among the members airlines actually value.
For travellers weighing where to focus their loyalty, the scale matters in a concrete way: bigger programs generally mean more partner airlines, more redemption options and better availability across alliances. United's Star Alliance reach, the multi-airline flexibility of Avios, and the sheer partner breadth of Flying Blue all flow from the scale these numbers represent.
