For domestic travel within the United States in 2026, a 15-year-old flying alone on JetBlue does not technically need to show a photo ID to pass through the TSA security checkpoint, as the TSA does not require identification for minors under the age of 18. However, it is highly recommended to carry a birth certificate or a school ID as "prudent" proof of age and identity. While the TSA is lenient, individual airlines like JetBlue may occasionally ask for proof of age to verify that the passenger is eligible to travel as a "young traveler" (ages 14+) rather than an "unaccompanied minor" (ages 5–13). If the minor is eligible for TSA PreCheck, they must show an acceptable government-issued ID to receive expedited screening. If the flight is international, the birth certificate is insufficient; a valid passport is mandatory regardless of age. For a 15-year-old traveling alone domestically on JetBlue, the birth certificate serves as an excellent backup to ensure a smooth check-in process, but their presence and boarding pass are usually the only requirements to clear security and board the aircraft.