Kids under 14 According to the Transportation Security Administration, kids are not required to show any identification at TSA checkpoints; still, some airlines require a birth certificate for children under 14 to prove their age. To avoid any hassles, travel with at least a copy of your child's birth certificate, or for the best-case scenario, obtain a passport for your child.
Kids 15 to 17 While kids 15 to 17 are still considered minors in the eyes of the TSA, some airlines require that they have some kind of identification when they're traveling alone. The rules can be somewhat looser than for adults; a school-issued ID card or a library card may be all that is required. For teens traveling alone, be sure to check with your individual airline. It’s always better to come prepared and not risk being turned away at the airport — be sure to keep your kid’s paperwork as up-to-date as your own!