Although a lawful permanent resident of the United States – AKA green card holder – cannot hold a U.S. passport until they become a citizen through naturalization, having a valid passport from your country of origin makes international travel much easier. It's the only universally accepted method of photo ID for travel outside the country, and when paired with your green card, it makes visiting a foreign country simple and easy. If your passport has expired, you can still visit Canada – but only by certain means, and only if you can provide other valid photo ID.
No Air Visits Without a Passport
Always remember to check the expiration date on your travel documents. You can't travel to Canada by air with an expired passport . Here's why: Although U.S. green card holders don't need a valid visa to enter Canada, you do need an electronic travel authorization, or eTA, to enter by air. And to get that eTA you need an unexpired passport from your country of origin, which you must also present for verification when you enter the country, along with your green card.
You Can Visit By Land and Sea
The requirements for entering Canada by land (driving), rail, or sea (including cruises) are more lax. All you have to do is prove your lawful permanent resident status – easily done with your permanent resident card – and provide photo ID.
If your passport were valid, it would serve as photo ID. But you can also use other government-issued IDs, such as a driver's license or military ID.
Note: In some circumstances, a U.S. citizen can use a birth certificate for proof of citizenship when entering Canada, but green card holders cannot.
Conditions for Entering Canada
Be aware that even if you present the proper documents at the border, you (and anyone else) may be denied entry to Canada if the border officers determine you fall into an "inadmissible" category. These are quite broad and include serious health problems, links to organized crime, a history of human or international rights offenses, and criminal convictions.
The best-known example of the latter is DUI, which usually precludes you from entry to Canada.
But you may still gain entry if you can convince the border officer that you have been rehabilitated, and in some circumstances you can be given a temporary resident permit that allows you to enter despite other excluding factors.
Getting Back Into the United States
Canadian law requires that you keep your identification and proof of U.S. lawful residency status with you while you're in the country. You'll need the same documents to get back into the United States at the port-of-entry.
As a general rule, most visitors to Canada are admitted for up to six months.
You can apply to extend this period, but lawful permanent residents of the United States who are out of the country for more than 180 days are subject to new immigrant inspection procedures.
If you're gone from the U.S. for more than one year, you'll need to maintain your eligibility for a reentry permit.
You will first need to fill out an application form and attend a biometrics appointment, from which point on the processing time for issuance of your permit will be several months, so be sure to plan for the application process in advance.
Permanent residents gone from the U.S. for over two years will need a returning resident visa.
For further information on and general FAQs, go to the U.S. Citizenship and Immigration Services webpage at uscis.gov, U.S. Customs and Border Protection at cbp.gov, the Department of Homeland Security at dhs.gov, or the Transportation Security Admission at tsa.gov.