Four 'scary' letters on airline boarding passes that passengers say they never want to see

Should you panic when you see “SSSS” printed on your boarding pass? Social media users are going viral for sharing their experiences after noticing the four letters upon arrival at the airport.

So, what does SSSS mean when it appears when you check in?

“SSSS are really four scary letters that no traveler wants to see on their boarding pass,” Zach Griff, senior aviation writer for New York-based travel blog The Point Guys, told Fox News Digital.

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“It stands for 'Secondary Security Screening Selection,' and is a measure implemented by security authorities in the United States to screen certain passengers with additional checks.”

The Transportation Security Administration (TSA) will screen passengers prior to official flight departure.

“Those selected for this enhanced security are chosen in the days leading up to a flight when airlines share the manifest with US security authorities,” added Greif.

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Griff says most people who get SSSS before a flight can't check in online and get a printed ticket from an agent — that's exactly what happened to Jordin Vergera and JT Mokarski, creators of the travel blog “The Mobile” Homie.”

“SSSS” stands for “Secondary Security Screening Selection”, which means the recipient must go through some additional security on their trip. (The Mobile Homey)

The travel-related duo from Arizona shared their experience on TikTok whenever they noticed the four S's on their boarding passes.

Whenever they received the SSSS on the boarding pass and posted it on social media, users flooded them with questions in the comment section.

Varzera and Mokarski told Fox News Digital about what this additional screening process entails.

The first time Varzera and Mokarski encountered four letters, only one of them was able to check before their flight.

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Vergera tried to get his boarding pass on the airline's app, but a notification popped up saying he needed to check in with a gate agent, he said.

The waiting process and additional security measures you have to go through with SSSS can take several hours. (istock)

Vergera said he was confused until he spoke to an agent.

“They had to give me a printed boarding pass [Mocarski] Can still use his digital, and then I had to carry this pass. It was marked and circled, and I had to show it every step of the way,” Vergera said.

“Instead of just going through one type of security … you had to go to the gate early, and they did extra in-depth screening when you left. But where the biggest thing was, once we got there, we actually ended up going through customs … and That's when the in-depth search began.”

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Vergera said every item she packed had to be removed from her luggage, including her toiletries. These items were then placed on a conveyor belt where everything was swabbed. He also had to turn on his laptop to get through security.

Vergera captured a video showing a crowded line in front of him as he waited three hours to receive his boarding pass after receiving the “SSSS” mark on his initial ticket. (The Mobile Homey)

“It was a little scary the first time,” he said.

Varjera had to arrive at the airport early and wait in line for three hours to get his boarding pass. He said it took him another hour to go through additional customs screening.

Back in April, when Mokarski went through the SSSS process in Rome, it was significantly faster, he said.

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“It depends on which country … or where you're going, the intensity of the search, what that entails,” Mokarski told Fox News Digital.

“SSSS can be completely random, and there is no way to know if you will be selected as SSSS when you book your flight.”

— Jack Grief, senior aviation writer for The Point Guys, a New York-based travel blog

Griff agreed with Mokarski, adding that it depends on the airport you're at, with some requiring early arrival and “full payment.” Some airports “may require an in-person interview with additional screening.”

Mokarski thinks social media has somewhat villainized the extra security measures, he said.

“At the end of the day, it's random, even with TSA agents, it's not like they're picking you. They know the remedies they have to go through to make sure they're checking,” Mokarski said.

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“It's just about staying calm and respecting their time. And they'll get back to you.”

“At the end of the day … they're just doing your job,” he added. “They're not there maliciously.”

Mokarski got his first “SSSS” marked on his boarding pass in April, and it only added an extra hour to his travel day, he said. (The Mobile Homey)

Grief said you can get SSSS for a number of reasons: “suspicious travel patterns such as frequent one-way international travel, or many visits to high-risk countries,” he said.

“SSSS can be completely random, and there's no way to know if you'll be selected as SSSS when you book your flight,” added Greif.

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Some people who received “SSSS” on their boarding passes have reportedly tried to apply for a redress number with the Department of Homeland Security in an effort to never see the letters again, according to several travel blogs. (Chip Somodevilla/Getty Images)

Vergera said people may worry about “SSSS” because they think the extra screening could cause them to miss their flight.

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He and Mokarski recommend getting travel insurance for this purpose.

They also said that when “SSSS” appeared on their boarding passes, the aircraft “waited” and did not leave any “SSSS passengers” behind.

Social media users are going viral for sharing their experiences with the dreaded “SSSS” that can appear on a boarding pass, meaning they've been selected to go through primary security. (The Mobile Homey)

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“I think for us, and we want to remind our friends that the journey is not perfect,” Vergera said.

“You grow the most when you're uncomfortable with the journey—just realize that it happens. Just roll with it and let it be part of your day … get through it and then [say]'I hope it never happens again.'

Fox News Digital has reached out to the TSA for comment.