International travel Some airlines automatically apply the unaccompanied-minor procedures to kids through age 17 on international flights, and charge the standard unaccompanied-minor fee if applicable. Children must usually have the same passport, visa or other international entry documentation required of adults.

For international travel, most major airlines allow children to travel "completely alone" without any special assistance once they reach 15 or 16 years of age. For children between 5 and 14, they are typically required to use the Unaccompanied Minor (UMNR) service. This service involves an airline staff member escorting the child through customs, security, and the boarding process, and handing them directly to the designated adult at the destination. The fees for this service in 2026 range from $150 to $250 per flight segment. Some airlines, like British Airways and Lufthansa, permit 12-year-olds to fly alone without the UM service, but this is rare for long-haul transoceanic routes. It is crucial to check the specific entry requirements of the destination country; for example, Mexico and South Africa require notarized "Consent to Travel" letters for any minor traveling without both parents, regardless of whether the airline considers them an "adult" or an "unaccompanied minor."