For many years, US and Canadian citizens were not required to present a passport to enter the United States. With the implementation of the Western Hemisphere Travel Initiative, all citizens of the United States, Canada, Mexico, and Bermuda will be required to present a passport or other accepted document that establishes the bearer's identity and nationality in order to enter or depart the United States from within the Western Hemisphere.
The Western Hemisphere Travel Initiative is being rolled out in phases.
Timeline for implementation of WHTI
January 23, 2007
All persons, including US citizens, traveling by air between the United States and Canada, Mexico, the Caribbean and Bermuda are required to present a valid passport to enter (or re-enter) the United States.
January 31, 2008
US Customs and Border Protection (CBP) ended the practice of accepting oral declarations of citizenship and identity alone at land and sea ports of entry.
June 1, 2009
Passport or other WHTI-compliant document (such as a passport card or trusted traveler card)is required for entry into the United States, including travel by land and sea (exceptions include some minors traveling by land, and cruise ship passengers on a closed-loop trip that begins and ends at same port in the US).
More frequently asked questions about Mexico travel documents and entry requirements:
