Passports are needed for any child who wishes to travel internationally. A child's passport is valid until he is 16, and can be used when traveling anywhere outside the United States. A passport is obtained for a child just as for an adult, through a passport agency or your local post office. Remember, this document expires at age 16, not 18.
If you are traveling with a child who is over 18, he needs a valid identification card. This card can be a passport card, military ID, driver's license or identification card. If he has a valid passport, this can also be used as photo identification when traveling on domestic flights.
A child traveling with his parent can use a birth certificate to prove age and identification. Anyone under the age of 18 does not need a photo ID to travel, but must prove how old he is. The birth certificate should match the name of the accompanying adult's identification as parent, if possible.
Any child traveling with one parent or an adult other than a parent must carry a note stating that he obtained permission to travel. Both parents must sign the note to show that the child can travel to another city or state. This is extremely important when the child is traveling with a friend's family, grandparent or other responsible, non-guardian adult.
