Air travel security plays a vital role in keeping millions of passengers safe every year. In 2025 alone, the U.S. Transportation Security Administration (TSA) screened more than 900 million travelers. While most passengers pass through security without any issues, some may notice a mysterious code printed on their boarding pass: SSSS.

If you've ever seen these four letters, or are worried about spotting them before your next flight, here's what you should know.

Understanding the SSSS Code

SSSS stands for Secondary Security Screening Selection, a designation used by the U.S. Department of Homeland Security. When this code appears on a boarding pass, it indicates that the traveler has been selected for additional security checks before boarding.

The designation can appear on both domestic and international flights. Travelers who receive the SSSS marker should expect more thorough screening than during standard airport security checks.

What Happens During Additional Screening?

Passengers selected for secondary screening may be asked to undergo various security procedures. These can include:

• Detailed inspections of carry-on luggage

• Swabbing electronic devices for testing

• Manual searches of personal belongings

• Additional body screening or pat-downs

The exact process varies from airport to airport and from passenger to passenger. In some cases, the extra screening may add only a few minutes to the journey, while in others it could take 30 minutes or more.

Because of these possible delays, travelers who notice SSSS on their boarding pass should arrive at the airport earlier than usual.

Why Are Some Travelers Selected?

Many passengers assume that receiving the SSSS designation means they have done something wrong. However, government reports suggest that this is often not the case.

A U.S. Senate report released in late 2023 found that many SSSS selections are made randomly. Although travelers on government watchlists or those with unusual travel histories may receive additional scrutiny, random selection remains a common reason for the designation.

The TSA uses a layered security strategy that combines visible and behind-the-scenes measures to protect air travel. Random screenings are one component of that broader security approach.

What If You Get SSSS Frequently?

Occasional additional screening is usually nothing to worry about. However, some travelers report receiving the SSSS designation repeatedly over multiple trips.

For those situations, the Department of Homeland Security offers assistance through its Traveler Redress Inquiry Program (DHS TRIP). This program was created for individuals who repeatedly encounter security screening issues, boarding delays, or identity-related travel complications.

After submitting an application and completing the review process, eligible travelers may receive a Redress Control Number. This number can be added to future airline reservations to help distinguish travelers from individuals with similar names or records.

While obtaining a redress number does not completely eliminate the possibility of future screenings, it can reduce the likelihood of repeated travel disruptions.

Other Reasons You Might Face Extra Security Checks

The SSSS code is not the only reason passengers may undergo additional screening.

TSA officers can also request further inspection if:

• An item in your luggage appears suspicious during X-ray screening

• A body scanner identifies something that requires closer examination

• A metal detector is triggered

• Airport personnel observe behavior that raises security concerns

Security officers are trained to identify unusual situations and investigate anything that could pose a risk to passengers or airline operations.

Can Trusted Traveler Programs Help?

Travelers looking to speed up the airport experience may benefit from enrolling in programs such as TSA PreCheck or Global Entry. These programs provide expedited screening benefits and can make the security process more efficient for eligible participants.

Although membership does not guarantee immunity from random screening, it can help reduce wait times and improve the overall airport experience.

Seeing SSSS on a boarding pass can be frustrating, especially when you're eager to start your trip. However, in many cases, the designation is simply part of the TSA's broader security strategy and may be assigned at random.

If you encounter it occasionally, allowing extra time at the airport is usually the best approach. For travelers who face repeated screenings, the DHS TRIP program may offer a solution that makes future journeys smoother and less stressful.