U.S. citizens can travel freely to and from Canada – as long as you have the right paperwork when you cross the border. If you're traveling for work, for school or with the intention of immigrating, you usually need a visa. But for tourism purposes, you can visit for up to six months with no visa. All you need is proof of U.S. citizenship and identification.

Valid Proof of Citizenship and ID

A U.S. passport, passport card or NEXUS card all serve as proof of both citizenship and identification. Of these, a passport is the best choice, because it's the only universally accepted travel ID. If you don't have one of these three documents, you can cross the border using your government-issued photo ID and one of the following documents to prove your citizenship: A U.S. birth certificate, certificate of citizenship or naturalization, permanent resident card or certificate of Indian status.

Traveling With Children

If you're traveling with children under 16, they only need to present proof of their U.S. citizenship at the border crossing. That said, Canadian officials are on the lookout for kidnapped or trafficked children, so be ready for some increased scrutiny when you travel with kids. If either of the custodial parents is not present – or if you're not a custodial parent or legal guardian of the child you're traveling with – bring a consent letter from the absent parent(s). The letter should state that you're authorized to travel with the child and include both parents' full names, addresses and telephone numbers.

Trusted Traveler Programs

For U.S. citizens who are members of the NEXUS or FAST trusted traveler programs, your NEXUS or FAST membership card serves as an alternative passport document when you travel into Canada by land. If you're a permanent resident of either the U.S. or Canada, you'll still need a passport or proof of permanent residence, in addition to your trusted traveler card, to enter Canada.

Tips for a Smooth Crossing

Heads up: Usually, crossing the border into Canada is as simple as filling out a form or verbally declaring your intentions and what you're bringing into the country. But you might be asked to fill out additional paperwork or to surrender your luggage for inspection. If that happens, you're responsible for handling the luggage, including opening, unpacking and repacking it. The good news is that you can avoid long waits by checking the Canadian government's list of U.S. to Canada border wait times, which is updated hourly. If you see a long wait at the nearest checkpoint, you have the option of entertaining yourself on the U.S. side of the border until the queue clears.

Who Can't Enter

You may have heard that people convicted of driving under the influence can't cross into Canada. That's generally true, but it applies to other crimes too. Canadian authorities reserve the right to deny entry to people with a criminal record including offenses like theft, assault, manslaughter, dangerous driving, driving while under the influence, and possession or trafficking of controlled substances. However, they can still let you in under certain circumstances, which usually boil down to convincing the Canadian border officers that you meet their legal definition of having been rehabilitated.