Tech-driven boarding: how boarding-pass codes influence seats, screening and passenger data

Recent industry observations show that small codes on boarding passes do more than confirm a flight. In an increasingly digital environment, these codes help airlines manage seating, boarding order and security processing. Experts say sequence numbers, group designations and security indicators are part of a broader, technology-driven approach to backstage operations that can affect a traveler’s experience, from seat assignment to screening time.

At the bottom of most boarding passes, a SEQ or sequence number indicates when a passenger checked in and, by some airlines’ rules, can influence seating if the flight fills up. For example, SEQ08 would denote the eighth person to check in. In systems that allocate seats in check-in order, late arrivals may find themselves in less desirable seats. Alongside SEQ, many passes also show a group label such as Group 1 or Group 2, used to call out priority boarding for families, travelers with disabilities, or different fare classes. Another code, SSSS, stands for Secondary Security Screening Selection and signals that a traveler will undergo a more thorough security screening in the United States, potentially adding time to the process. Airlines often overbook flights, and when everyone shows up, those who checked in last can be moved to another flight.

Beyond seating, the data on boarding passes includes the Passenger Name Record, or PNR, a six-character alphanumeric code that identifies a passenger within the airline’s reservation system. The PNR acts as a keyed itinerary, encompassing flight details, meal preferences and, in many programs, frequent-flyer status. While designed for operational efficiency, the combination of codes across boarding passes raises questions about privacy and data handling as carriers migrate to more automated boarding and digital wallets.

Industry observers emphasize that codes on boarding passes are part of a broader trend in aviation technology and AI-enabled operations. Airlines use scheduling and queue-management software, as well as predictive analytics, to speed up boarding and reduce delays. Passengers can find it useful to understand that what seems like a simple piece of paper or digital pass is a bundle of data points that feed into automated processes, from seat assignment to security screening and boarding gates.

Travelers are advised to review their boarding passes for codes that might affect their experience and to be mindful of baggage and seat rules.