Passengers can print a United Airlines boarding pass from a home computer if they choose the online check-in option. Online check-in is available starting 24 hours before the scheduled departure time.
As an alternative to the printed boarding pass option, passengers can request an email with a link to the boarding pass when departing from certain cities. Passengers can then display the boarding pass barcode on the screen of a mobile device at the security checkpoint and at boarding time.
The online check-in service for United Airlines is also available for passengers who need to check bags, but these passengers must stop by a ticket counter or curb-side skycap prior to boarding.