Gate agents help the airline to admit passengers through the gate as they board their flight. They may check boarding passes and cross-reference them to a passenger's identification documents to ensure that passengers board the correct flight.

Gate agents are the operational "command center" for a flight's departure. Before boarding begins, they coordinate with the incoming flight crew to ensure the aircraft is clean and ready. They manage the passenger manifest, handle last-minute seat assignments, and process upgrades or standby requests. One of their most critical duties is verifying travel documents—specifically ensuring that international travelers have the required visas or health declarations for their destination. They also make essential announcements regarding boarding zones, delays, or gate changes. Once boarding starts, they scan boarding passes and cross-reference them with the aircraft's weight and balance requirements. If a flight is overbooked, they negotiate with volunteers for rebooking. Their goal is to ensure an "on-time departure" while maintaining strict safety and security protocols.