The Western Hemisphere Travel Initiative (WHTI ) was passed in 2004, making it more difficult to cross the borders between the United States, Canada and Mexico. While the border between the United States and Canada was once semi-open and required only a valid I.D. to pass, the WHTI regulations require different documentation. These regulations went into effect for air travelers in 2007 and on June 1, 2009, for those traveling by land and sea.
Citizens of the United States wishing to cross the border into Canada must provide a U.S. passport, a U.S. passport card or an enhanced driver's license (EDL). A passport card is less costly than a full passport, but can only be used at land and sea entry ports. Several U.S. states now offer enhanced driver's licenses, which function as a statement of U.S. citizenship.
U.S. (and Canadian) citizens may also apply for the NEXUS program, which pre-approves low risk travelers for expedited processing and clearance at airports and other areas where you may come into the country. You must also present tickets or documents that facilitate your travel back to the United States or to another country after Canada. No vaccinations are required for American Citizens wishing to travel to Canada.
Canadian citizens who wish to cross the border into the United States must present a Canadian Passport or an enhanced driver's license, which Canadian provinces now issue. The EDL may only be used at land or sea entry points.
Canadian citizens are also eligible for the NEXUS program. Canadians do not need vaccinations to enter the United States. When crossing the border into the U.S., Canadians must provide a return ticket to Canada or another country, or state the amount of time they intend to stay in the United States.
Permanent Residents or Foreign Nationals
Permanent residents of another nation who are currently in the process of applying for U.S. or Canadian citizenship must enter either country under the rules of their country of origin, even though they are currently living permanently in the U.S. or Canada. This includes carrying a passport from their country of origin. The same rules apply for foreign nationals entering one of the two countries from the other.