The "group number" on your boarding pass is a critical piece of information that dictates exactly when you are permitted to board the aircraft. Airlines use this tiered system to streamline the process, reduce gate congestion, and manage overhead bin space. Typically, groups are numbered from 1 to 6 or 8, with lower numbers boarding earlier. Group 1 is almost always reserved for first-class passengers and top-tier elite frequent flyers. Group 2 often includes mid-tier elites and those with co-branded credit cards. In 2026, many major airlines like United use a "WILMA" system for the remaining groups: Group 3 (window seats), Group 4 (middle seats), and Group 5 (aisle seats), which helps fill the plane from the outside in to prevent passengers from having to climb over one another. Group 6 and above are generally reserved for Basic Economy passengers or those who checked in last. Families with young children, active military, and passengers with disabilities are usually invited to "pre-board" before Group 1. It is important to wait until your specific group is called on the digital screens or by the gate agent, as boarding out of turn can delay the process for everyone else.