Traveling used to be fun back in the past, but these days getting through the airport security is a pain. And now, it is going to get tougher for travelers who find ‘SSSS’ stamped on their boarding passes. In the simple terms, airline passengers flying into the United States will face extra security checks and delays if “SSSS” is printed on the bottom of their boarding pass.

The passengers whose boarding passes bear SSS are pre-selected to undergo additional security screening process – which can involve bag searches, pat downs and validating identity and take up to half an hour – before boarding their flight.

A TSA (Transportation Security Administration) spokesman told Business Insider in a statement:

“SSSS stands for Secondary Security Screening Selection and it appears on a passenger’s boarding pass when they’ve been selected by TSA’s Secure Flight system for enhanced security screening.

“Secure Flight is a risk-based passenger prescreening program that enhances security by identifying low and high-risk passengers before they arrive at the airport by matching their names against trusted traveler lists and watchlists. Secure Flight is also used to prevent those on the No Fly List and the Centers for Disease Control’s Do Not Board List from getting on planes.”

The system was introduced after the 9/11 terror attacks to help security officials monitor potentially dangerous individuals from entering or leaving the U.S. The TSA insists travelers who receive the ‘SSSS’ are selected at random, but some have claimed they are pulled aside most times they travel.

Passengers may be able to tell they will have to undergo additional checks if they are unable to print their boarding pass at the airport’s self-check-in. Out of many factors that might get travelers the SSSS, a few notable ones are:-

  • If you book the ticket via cash.
  • If you buy a one-way ticket.
  • If you are flying to or returning from a high-risk country.