What the “SSSS” Code on a Boarding Pass Indicates and Why Travelers Sometimes See It

selected for more detailed screening. This is not a suggestion or a minor extra step. It is a mandatory process that overrides standard screening, even for passengers who are normally eligible for faster security lines through programs such as TSA PreCheck or Global Entry. In many cases, travelers with this code cannot complete check-in entirely online or through a mobile app. Instead, they are required to check in at the airport so an agent can verify their identity and documents in person before the security process continues.

This extra screening is part of the Secure Flight program, a system that