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.

For international travel in 2026, a child of any age (including newborns) must have their own valid passport. Many countries also require a visa or an Electronic Travel Authorization (ETA) depending on the child's nationality. A critical document often overlooked is the Minor Consent Form; if a child is traveling with only one parent, or with a grandparent/guardian, many border agents require a notarized letter from the non-traveling parent(s) authorizing the trip to prevent international child abduction. For domestic U.S. flights, children under 18 generally do not need a photo ID, but it is highly recommended to carry a copy of their birth certificate to prove their age (especially for "lap infants" under 2). If the child is traveling as an "Unaccompanied Minor," you will need a specialized airline form and a photo ID for the person dropping them off and picking them up. Always check the specific requirements of your destination country, as some (like South Africa or Brazil) have extremely strict "unabridged birth certificate" laws that can result in boarding being denied if the proper paperwork is missing.