When does boarding start United? United Airlines begins boarding 30 to 50 minutes before departure. Moreover, the boarding procedure depends on the flight type and aircraft type. However, when does boarding start United is a common question among travelers trying to plan their airport arrival. United board passengers based on their groups, starting with Premier members, followed by window seat passengers, then middle and aisle seats. Read more: https://www.airlinesgrouptravel.com/blog/united-airlines-boarding-group #unitedairlinesboarding #unitedairlinesboardingroups