A membership account identifier assigned by airlines or airline alliances to individuals participating in their loyalty programs. It serves as a unique record key, tracking accumulated miles or points earned through travel, purchases, or other qualifying activities. As an example, a passenger enrolled with United Airlines’ MileagePlus program will receive a distinct alphanumeric sequence which, when presented during booking or check-in, ensures proper crediting of flight activity to their account.
This identifier is crucial for accessing program benefits, which may include priority boarding, complimentary upgrades, access to airport lounges, and award travel. The proliferation of these programs began in the early 1980s, transforming the travel industry by incentivizing customer loyalty and providing airlines with valuable data for marketing and operational optimization. The systematic capture of travel data underpins personalized services and targeted promotions.
