Canada and Mexico are the United States’ nearest neighbors and many Americans will cross the northern and southern borders at some point. Although both Canada and Mexico are part of the Western Hemisphere Travel Initiative, regulations for air travel are tougher than those for crossing land and sea borders. Ensure you have the correct documentation before you travel to avoid problems or delays during your trip.

Passport Book

A passport book is the one identification document you can use at all international borders, including when traveling by air. This is true for all travelers, including children under the age of 16. If you are a citizen of a country other than the United States, your national passport is an acceptable form of identification for travel between the United States and both Canada and Mexico.

Passport Card

Although the State Department advises that passport cards are not an appropriate form of identification to fly to Canada or Mexico, Mexican immigration regulations do allow you to use a passport card to enter the country by air. However, although your passport card is valid for returning to the United States by land or sea, you won’t be able to use it to return by air, making a passport book a more practical option. You cannot use a passport card to fly to Canada, although it is valid for land and sea border crossings.

NEXUS Card

NEXUS is a joint U.S.-Canadian project that aims to streamline the border-crossing process. The NEXUS membership card includes a radio-frequency identification unique to you, and if you consent to undergoing an iris-capture procedure, you can use it to enter Canada by air. You’ll have to undergo law enforcement and criminal history checks in both countries as part of your NEXUS application, but your card will expedite your entry into Canada.

Traveling With Children

If you’re traveling with a child that’s not yours or are alone with your own child, U.S. Customs and Border Protection strongly recommends carrying a parental note. If the child’s parents are not present, both should sign it, while for a child traveling with one parent, the absent parent should sign. The note should read, “I acknowledge that my wife/husband/etc. is traveling out of the country with my son/daughter/group. He/She/They has/have my permission to do so.” Although carrying this document is not a legal requirement, if you can’t show it, Customs and Border Protection staff could detain you until they can verify that the child has permission to leave the United States