This guide is informational, not legal advice. Verify Travel.State.gov, INM, CBP, airline, bus, rental-car, insurance, and event guidance before match travel.

U.S. citizens entering Mexico by land should carry a passport book or passport card. The U.S. passport card is for land and sea travel from Canada, Mexico, Bermuda, and some Caribbean countries; it is not valid for international air travel.

For Mexico entry, the State Department says travelers must apply for an FMM or entry permit online or from an INM office, including travelers staying near the border area. Verify current INM handling for your route and stay length.

Vehicle planning can matter as much as documents. Check Mexican auto insurance, rental-car permission, vehicle import rules if leaving the border zone, medicines, minors' letters, pets, and prohibited goods before crossing south.

For Southern California and Baja trips, compare San Ysidro, Otay Mesa, Tecate, Calexico West, and Calexico East. For Texas and northeastern Mexico trips, compare Laredo, Colombia Solidarity, Hidalgo, Pharr, and Brownsville before choosing a bridge.

For the return north, U.S. citizens entering the United States by land or sea need a WHTI-compliant document. SENTRI or Ready Lane can help only when every traveler and the vehicle match the lane rules.