Traveling with United Airlines? Its boarding process is straightforward once you know about the system. It starts with pre-boarding for those who need extra assistance, like unaccompanied minors, families with children, or active military personnel. United Airlines Boarding Groups come into play with Group 1, which is reserved for Premium passengers. Group 2 includes Premier Silver members, as well as travelers with Premier Access or eligible credit cards for priority boarding. After that, Groups 3 to 5 are for Economy Plus and economy passengers, based on seat location: window seats, middle seats, and aisle seats. Group 6 is for Basic Economy passengers, who board last.