Book a United flight online when you can, call when you can’t. The reservations line is 1-800-864-8331 (1-800-UNITED-1) and it runs 24/7, but phone bookings carry a $25 fee per ticket on standard fares, and you’ll do better on united.com or the app for most trips. Where the phone earns its place: complex itineraries, MileagePlus award redemptions involving multiple partners, accessibility requests, and last-minute changes when the website chokes. Everything else — domestic one-ways, round-trips, simple fare comparisons — is faster self-serve.
In This Article
The reservations numbers
The main line for new bookings and existing reservation changes is 1-800-864-8331. You can also use 1-800-241-6522 — it’s an older number still listed for reservations and routes to the same agent pool. The international reservation line is 1-800-538-2929 for callers in Mexico and select Latin American countries; United publishes a full country-by-country list on its international reservations contact page.
For specialty bookings:
- MileagePlus award tickets: 1-800-421-4655 (use for complex awards with mixed cabins or Star Alliance partners)
- Group bookings (10+): 1-800-426-1122
- Unaccompanied minor: book through the main line, request the service at booking
- Pet travel (in-cabin): add to an existing booking via main line, pet space sells out on popular routes
Hold times on the main line run 15 to 45 minutes most days, longer during IROPS. If you’re calling purely to book (not for an existing reservation issue), weekday mornings Pacific time are surprisingly quiet — East Coast commuters aren’t at their desks yet.
When to call instead of booking online
Website first, phone second. The site handles 95% of what a leisure traveller needs. Where calling is worth the wait:
Multi-stopover itineraries. If you want JFK-Frankfurt-Cairo with a 72-hour Frankfurt stopover, the site’s search engine may not surface the combination. Agents can price it as one ticket, which matters for baggage and connection protection.
Award redemptions with partners. United’s site shows MileagePlus awards on United metal and most partner flights, but not all. If you’re trying to fly Lufthansa, Singapore Airlines, or ANA on MileagePlus miles and the site says no availability, call — agents can see space the public site doesn’t, especially in premium cabins.
Accessibility and special-needs bookings. Wheelchair assistance, service animals, medical equipment, specific seat requirements — all handled better by voice.
Date changes on non-refundable tickets. You can do most changes online now, but complicated scenarios — rebooking after a missed connection, combining two one-ways, or using a travel credit from an old ticket — still go faster by phone.
What to have ready before you call
Five minutes of prep saves twenty on the call:
- Your MileagePlus number if you have one. Punching it in the IVR routes you to the right queue and pulls up your profile.
- Specific dates and cities — not ranges. “I want to fly DEN to ORD on 14 June, coming back 18 June, economy.” Saying “sometime in June, maybe around Father’s Day” means the agent has to search multiple permutations.
- A credit card ready. Phone bookings require payment during the call. No 24-hour hold like the website offers, unless you’re MileagePlus Premier 1K or above.
- Passport details for international. Name exactly as on the passport, number, expiry. Getting one letter wrong forces a reissue and sometimes a fee.
- Names and DOBs for every passenger. Middle names matter on international tickets.
If you’re calling about an existing booking, have the confirmation code (six letters and numbers) on hand. The IVR will prompt you for it, and having it keyed in drops you into a queue where the agent already has your record open.
Booking online — the approach that saves money
For most trips, united.com will get you a better fare than the phone. The $25 phone booking fee matters on a $200 domestic ticket. More importantly, the site’s Flexible Dates search (click “My dates are flexible” before searching) shows a calendar of prices so you can shift a trip two or three days for real savings.
Mobile app bookings get you the same fares as the website plus better handling during disruption — the app pushes rebooking options the moment United cancels on you. Both accept MileagePlus miles, travel credits, and ETCs (electronic travel certificates from previous cancellations).
One catch: the cheapest Basic Economy fares come with no changes, no cancellations (after 24 hours), no upgrades, no refunds. They also don’t get overhead bin space on most domestic flights, so the “cheap” ticket can cost $40 extra in checked-bag fees. Read the fare rules before clicking buy.
The short version
- Main reservations: 1-800-864-8331 (24/7)
- MileagePlus awards: 1-800-421-4655
- Phone booking fee: $25 on standard fares
- Best phone-booking time: weekday mornings PT
- Default to: united.com or the United app
- Call when: complex routings, partner awards, accessibility, disruption
If your call is about getting through to a human rather than booking fresh, see our guide on how to talk to a real person at United Airlines — the same number, different menu tactics. Numbers verified April 2026 against United.com’s published contact pages.
