What ID Is Required for International Flights?
Traveling overseas is an exciting experience, but to get on the plane, you'll need the proper form of identification. Always make photocopies of your ID before leaving home, and if possible, email them to yourself so they can be easily accessed if the originals are lost. To prevent theft or loss abroad, store you passport in a money belt worn beneath your clothes.
Passport
To fly to another country, including Canada and Mexico, American citizens must have a valid passport. Avoid trouble by applying for your passport well in advance of your trip overseas, as it can take weeks or even months to procure one. If you already have a passport, consider renewing it if it's valid for less than six months after you're scheduled to return, as many countries will not accept passports set to expire shortly.
Children and Babies
All children, even babies, require their own passport to travel overseas via air and cannot do so using the passport of a parent or guardian. To apply for a passport for a child under 16, both parents must accompany the minor to an application center. If one parent cannot do so, he'll need to send a notarized statement of consent, according to Baby Center. Single parents will need to provide evidence of their legal status, like a sole custody agreement.
TSA ID
When you pass through Transportation Security Administration screening points on your way to catch an international flight, you may use a passport or another form of approved ID. For instance, a driver's license, military ID, Native American tribal ID, permanent residence card and a state-issued ID are all acceptable for use at airport security checkpoints. However, to actually board your flight overseas, you will need to present a valid passport.
Visas
Though a visa is not a form of ID, it does identify you as a person allowed to visit, study or live in the country to which you are flying. Not all countries require Americans to have visas for short visits, but others do, and most mandate them for longer stays due to marriage, work or school. To avoid being sent back to the US, research the visa requirements for the countries you'll be visiting.