Typically, minors under the age of 18 do not have to present identification for domestic U.S. travel. Airlines will accept identification from the responsible adult on behalf of the minor(s). For international travel, minors under the age of 18 must present the same travel documents as the adult.

Whether a 14-year-old can fly alone without a passport depends entirely on the destination and the nature of the flight. For domestic flights within the United States or within most single countries (like the UK or Canada), a passport is generally not required for a minor. In the U.S., TSA does not require children under 18 to provide identification when traveling with a companion or alone domestically; however, airlines often suggest carrying a birth certificate or a school ID just in case. For international flights, a 14-year-old must have a valid passport, regardless of whether they are flying alone or with an adult. Furthermore, many countries require a notarized "Consent to Travel" letter signed by both parents if a minor is traveling solo or with only one parent, to prevent international parental child abduction. While the child might not need a government-issued photo ID for the airport security line in a domestic setting, they absolutely need the legal travel documents required by the destination country's immigration laws.