United Airlines allows check-in beginning at 24 hours before the originally scheduled flight time. Customers must check in no less than 30 minutes before departure in most cases; in some major airports, 45 minutes is the limit.
Customers can check in online, on a mobile device with Internet capability or at the airport. In most cases, an email is sent prior to check-in with a reminder for the customer; use the link in the email or provide the required information online to check in to the flight. To check in at the airport, use a kiosk or speak to an attendant at the United counter, providing the requested information to check-in.
If checking baggage, customers may check in prior to arriving at the airport, then check baggage at the airport. Remember to label all bags with pertinent information before checking them. Additionally, you may check-in to the flight prior to arriving at the airport, then print any tickets at the airport using a United kiosk.
Because check-in occurs prior to passing through security, fliers should plan for enough time to check in and clear security before the scheduled departure. Holidays and heavy vacation travel times may increase the time it takes to get through security, so plan accordingly.