U.S. border crossings

As of Jan. 31, 2008, all persons crossing land borders or sea borders into or out of the United States must show appropriate documents proving citizenship and identity.

Acceptable documents include a passport, a Trusted Traveler Card (NEXUS, SENTRI or FAST) or a military ID with travel orders. If a passport is not available, then U.S. citizens can show a government-issued photo ID (such as a driver’s license) and a birth certificate or naturalization certificate.

Border crossing personnel are allowed some latitude in enforcement (if the travelers can establish his identity clearly enough) at first.