Cannabis & the US–Canada border
Never cross the border with cannabis. In either direction. Full stop.
Cannabis is legal in Maine and in Canada — but the border is federal, and U.S. federal law still classifies cannabis as illegal. State and provincial legalization is irrelevant at the port of entry. It does not matter that both sides have legalized it.
Seizure & fines
Even a small amount can be confiscated, with fines that can reach into the thousands.
Denied entry
CBP can refuse admission, detain, or arrest travelers carrying cannabis.
Lifetime ban
Non-citizens can be found inadmissible — even for admitting past use — and banned for life.
CBD counts too
CBD oil and derivatives have triggered seizures and lifetime bans at the border.
Why state law doesn't help you here
International travel is governed by U.S. federal law, which supersedes state law. Because cannabis remains federally illegal, bringing it to a U.S. port of entry — by car at a crossing like Houlton, Calais, or Madawaska, or by air — can mean denied admission, seizure, fines, and apprehension.
It cuts both ways: Canada (CBSA) also penalizes travelers who cross into Canada with cannabis without proper authorization. Leave it behind on whichever side you bought it.
If you're visiting Maine to consume
- Buy and consume in Maine; do not take it with you when you leave the country.
- Don't drive across the border with product in the car, glovebox, or trunk — "I forgot it was there" is not a defense.
- Don't carry CBD across either, despite how it's marketed.
- Answer CBP questions honestly — but know that admitting use can carry consequences for non-citizens.
General information for adults 21+, not legal advice — border enforcement is at the officer's discretion and rules change. Sources: U.S. Customs and Border Protection, "Marijuana Remains Illegal in the United States"; U.S. Embassy & Consulates in Canada.