Lonely Planet Writer

Why you don’t want to see these four letters on your boarding pass if you are heading to the US

Travelers heading through US airports should keep an eye on their boarding pass for four letters that could make the airport experience a lot more frustrating: SSSS.

Travelers move through one of the Transportation Security Administration lines at Ronald Reagan National Airport. Image by Chip Somodevilla / Getty Images

The dreaded four-letter combo means a passenger is among the unlucky people pre-chosen for secondary security screening selection. The TSA’s Secure Flight system’s secondary screening program has been in place for some time, but many people are still confused when they see the letters on their boarding pass – and the delays that extra screenings can lead to.

”Secure Flight is a risk-based passenger pre-screening 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,” a TSA spokesperson told Lonely Planet in a statement. Travelers say that it means needing to get to the airport early in order to deal with potential delays caused by the extra security checks.

The extra screenings can include enhanced pat-downs, having carry-on luggage inspected by hand, and in the case of items that cannot be X-rayed, officers may perform a test for possible explosive materials. The person conducting the screening may also use a hand-held metal detector to search the passenger for metal objects. The screenings have affected people like Irish politician Gerry Adams and BBC reporter Bahman Kalbasi, both of whom have posted about it on Twitter.

The TSA says that to protect travelers’ privacy, the program only collects the minimum amount of personal data – like name, date of birth and gender – needed “to conduct effective matching”. The program sends screening instructions back to airlines to help identify travellers who are eligible for TSA Pre-Check, people who will end up getting an enhanced screen, and those who will get a regular old screening. That’s why the code ends up on a boarding pass. The process also stops people on the No Fly List and Centers for Disease Control and Prevention Do Not Board List from boarding an aircraft.

For travelers who have been subjected to repeated secondary screenings and want it to stop, the TSA says that affected travelers can use the Travel Redress Program to help find a resolution for travel-related screening or inspection issues.