United Airlines Check-In: Online, Mobile Airport Check-In Guide

Checking in for a United Airlines flight is straightforward and can be done in several convenient ways, helping you secure your boarding pass, select seats, add checked baggage, and prepare for your trip with minimal hassle. The process is designed to save time at the airport, especially when you use digital options.

When Can You Check In?

United Airlines typically opens online check-in and mobile check-in exactly 24 hours before your flight's scheduled departure time (based on the local time at the departure airport). This window closes about 60 minutes before departure for most flights, though airport-specific minimum check-in times apply—especially if you're checking bags or traveling internationally.

• For domestic U.S. flights: You must complete check-in at least 45 minutes before departure (this applies whether or not you're checking bags, as updated in mid-2025 for consistency).
• For international flights: The cutoff is usually at least 60 minutes before departure, but some airports require earlier arrival (e.g., 75–90 minutes at certain international hubs).

In cases where your name on the ticket doesn’t match your ID, you may need to correct it before check-in. See our detailed United name change policy. Always aim to check in as soon as the window opens at the 24-hour mark for the best seat choices, potential upgrades (if eligible), and to avoid any last-minute issues.

How to Check In Online or via the United App (Recommended)

The easiest and most popular method is online check-in through the United website or the free United mobile app.

• Visit united.com or open the United app.
• Sign in with your MileagePlus account for faster access (it pulls up your trips automatically), or enter your confirmation number (6-character code) and last name.
• Select your flight and follow the prompts: Declare any hazardous materials, choose or change seats (note: some seats may require payment, especially in Basic Economy), and add or pay for checked baggage if needed.
• Review your details and complete the process.
• Receive a digital boarding pass—save it to your phone's wallet, screenshot it, or download it. You can also print it if preferred.

Benefits of the app include real-time flight updates, bag tracking, terminal guides, and easier modifications to your trip.

2. Mobile Check-In (Via United App)

Downloading the United app lets you check in on your phone:

• Open the app on your iPhone or Android
• Tap “Check-In”
• Enter your last name and booking code
•  Download your mobile boarding pass

Once checked in, the boarding pass stays on your phone — even offline — and automatically updates with any seat changes or gate updates.

Other Check-In Options at the Airport

If you prefer not to check in online, or if your situation requires assistance:

• Airport Self-Service Kiosks: Available at most United airports. Scan your ID or enter your confirmation number to check in, select seats, pay for bags, print your boarding pass, and get luggage tags.
• Check-In Counter / Agent Desk: Ideal for special needs (e.g., groups, families with minors, pets, or travelers requiring assistance like wheelchairs). Provide your booking details and ID; agents handle everything, including printing boarding passes and tagging bags.
• Curbside Check-In (available at many U.S. airports): Drop off bags outside the terminal using your confirmation number and ID for a quicker start.

Even if you check in online, use kiosks or bag drop shortcuts to drop off checked luggage quickly. If you’re traveling with a baby, learn how to add an infant to your itinerary before check-in on the United infant policy page.

When Should You Check In?

Online & Mobile: Opens 24 hours before departure and closes about 60 minutes prior.
Airport Check-In: Counters and kiosks usually open 3 hours before departure — especially for international flights.

United updated their policy requiring passengers on domestic flights to complete check-in at least 45 minutes before departure (whether you check bags or not), and 60 minutes before for international flights. If you miss these windows, you risk being denied boarding. Passengers with pets often require special documentation before they can check in. Check the add pet to United flight guide. 

Key Tips for a Smooth United Check-In

• Boarding Pass: Go digital for convenience—it's accepted at security and gates. Have a backup printed copy or screenshot in case of phone issues.
• Baggage: Add checked bags during check-in and pay any fees (allowances vary by fare and route—e.g., many international flights include one free checked bag, even in Basic Economy, except to certain destinations like China or Tahiti). Check weight/size limits to avoid extra charges.
• Required Documents: Bring a valid government-issued photo ID (REAL ID compliant for domestic flights after relevant deadlines). For international travel, have your passport, visa, and any required entry documents ready—some may need agent verification.
• Special Situations: Online check-in may not be available for unaccompanied minors, travelers with pets, those needing special assistance, or certain international trips requiring document review. In these cases, arrive early for in-person check-in.
• If your travel plans change after booking, you should review the United flight change policy before you check in
• Pro Tips: Download the United app in advance for notifications. Arrive at the airport 2 hours early for domestic flights and 3 hours for international (more during peaks or holidays). Monitor your flight status for delays or changes.

By checking in early and using the online or app method, you'll breeze through the airport and focus on enjoying your trip. Safe travels with United Airlines!