United Airlines flies passengers and cargo across North America and to Asia, Europe, Africa, the Pacific, the Middle East and Latin America. Its hubs are Chicago O'Hare, Denver, Houston, Los Angeles, Newark, San Francisco, Washington Dulles and Guam. Smaller regional airlines, such as SkyWest and Republic, fly shorter routes under the United Express name on contract, which lets United serve smaller cities that feed its hubs.
Nearly all of the parent company's revenue comes from the airline. Besides ticket sales, United earns money from carrying freight and mail and from its MileagePlus loyalty program, which sells miles to partners such as Chase, the issuer of its co-branded credit card. Members used about 10.9 million MileagePlus flight awards in 2025. United also sells maintenance, ground handling and flight training to other companies. It competes with other US airlines, which can push it to match discounted fares, and with foreign carriers on international routes.
United belongs to the Star Alliance and runs joint businesses with Air Canada, Lufthansa, ANA and Air New Zealand that share routes and revenue. It had about 113,200 employees at the end of 2025, roughly 83% of them represented by unions.