In 2026, the requirements for a 15-year-old to use TSA PreCheck depend on whether they are traveling with an adult. If a 15-year-old is on the same flight reservation as a parent or guardian who has TSA PreCheck, the teen can typically use the PreCheck lane even if they do not have their own membership, provided the PreCheck indicator appears on their boarding pass. However, if the 15-year-old frequently travels alone (as an unaccompanied minor), they are encouraged to apply for their own Known Traveler Number (KTN). To apply, they need a parent's consent, an online application, and an in-person appointment at an enrollment center. During the appointment, they will need a valid passport or a combination of a birth certificate and a school photo ID. Once enrolled, the membership lasts for 5 years. For teens traveling with family, it is vital that the parent’s KTN is entered correctly into the airline's reservation system so the "TSA PRE" mark is triggered for the entire group, though this is not always guaranteed for children over the age of 12.