United Airlines: Hubs, Baggage, Check-In & Booking Guide

United is a major U.S. carrier and founding member of Star Alliance, the world's largest airline alliance, giving it broad reach through partners like Lufthansa, ANA, and Singapore Airlines. It operates a particularly strong long-haul international network from its coastal and central U.S. hubs.

United's hubs include Chicago O'Hare (ORD), Denver (DEN), Houston (IAH), Newark (EWR), San Francisco (SFO), Los Angeles (LAX), and Washington Dulles (IAD) — a spread that supports strong connectivity to both Asia and Europe.

United serves an extensive network across North America, Latin America, Europe, Asia, and Oceania, both directly and through Star Alliance partners.

Baggage allowances vary by fare class, route, and MileagePlus status. Basic Economy fares are typically the most restrictive on carry-on and checked bags — confirm the current policy for your specific fare before flying.

Check-in is available online, through the United app, at airport kiosks, or at the counter. Online check-in typically opens 24 hours before departure, and the United app is commonly used for live flight status and gate changes.

United offers Basic Economy, Economy, Economy Plus (extra legroom), United Premium Plus, Business, and United Polaris (its long-haul premium cabin) on select international routes.

Bookings made at least 7 days before departure can typically be cancelled free within 24 hours of booking, under U.S. DOT rules. United generally doesn't charge change fees on most Economy and above fares for domestic and many international itineraries, though fare differences may apply.