You're Deemed Suspicious Prior to Check-In This could happen for a varietyof reasons. The TSA, as well as airports around the world, identify certain behaviors as suspicious. There is an extensive list of about 92 of these behaviors in the U.S., but the most common ones are: Paying for any of your tickets in cash.

If you find yourself frequently subjected to secondary screening, it is likely due to either a "random" selection algorithm or specific "Red Flags" in your travel patterns. The most common indicator is the "SSSS" code (Secondary Security Screening Selection) appearing on your boarding pass. This can be triggered by booking a last-minute flight, purchasing a one-way international ticket, paying for a flight in cash, or having an unusual itinerary (like flying into one city and out of another). Another common reason is a "name mismatch," where your name is similar to someone on a government watch list. For some, it is simply bad luck within the TSA's random selection process. If this is a persistent issue, you can apply for a Redress Number from the Department of Homeland Security, which helps differentiate you from others with similar names and can significantly reduce the frequency of these "Selectee" designations during your pre-flight routine.