When flying with United Airlines, knowing how early you can check in is important for a smooth travel experience. United offers several check-in options, including online check-in, mobile check-in through the United app, airport self-service kiosks, and check-in counters. The earliest and most efficient method is online check-in, which opens 24 hours before your scheduled flight departure and closes one hour before domestic flights and 90 minutes before international flights. To check in online, passengers enter their confirmation number and last name on the United website or app. During online check-in, travelers can select seats, add checked baggage, and get a digital boarding pass. This method is recommended for passengers with carry-on bags only, as it allows them to skip the check-in counter and go straight to security.

For passengers with checked baggage, online check-in is still beneficial. Once checked in online, travelers can use the bag drop counter at the airport. These typically open three hours before departure and close 45 minutes before domestic flights and 60 minutes before international flights. United advises passengers to arrive at the airport at least two hours before a domestic flight and three hours before an international flight, giving enough time for baggage drop, security screening, and boarding.

For those who prefer airport check-in, United provides self-service kiosks and staffed counters. Self-service kiosks open three hours before departure and allow passengers to check in, select seats, pay for baggage, and print boarding passes and bag tags. These kiosks are a convenient option for those who didn’t check in online. Staffed check-in counters are available for travelers who need personal assistance, have special requirements, or are traveling with items like pets or oversized luggage. These counters follow the same check-in and baggage deadlines and are open several hours before flight time.

Boarding deadlines are also enforced. For most United flights, boarding ends 15 minutes before departure for domestic flights and 30 minutes before international flights. Even if you have checked in and received your boarding pass, arriving late at the gate may lead to denied boarding. It’s important to allow enough time to get through security and reach your gate before boarding closes.

In summary, you can check in for a United flight as early as 24 hours before departure using the website or app. Airport kiosks and counters open three hours before flight time. United’s deadlines require passengers to complete check-in at least one hour before domestic flights and 90 minutes before international flights, with bag drop and boarding closing earlier. To ensure a smooth travel experience, it is best to check in early, arrive at the airport with enough time, and follow all airline instructions carefully. United’s multiple check-in options offer flexibility and convenience to help travelers prepare for their flights with ease.