Dual citizen Canadians must show a Canadian passport to enter the country under tightened entry rules effective September 30.

In years past, the government said that dual citizens often entered Canada using their foreign passports backed up by a citizenship card or a provincial driver’s licence to confirm they were Canadian citizens. Now, this practice will end for dual citizens flying into Canada.

Without a proper Canadian passport, Canadian citizens will not be allowed to enter the country as part of a new electronic travel authorisation system.

In a new advisory, the Canadian government warned that “Canadian citizens will need to have appropriate documents to travel to Canada before they can board their flight. A valid Canadian passport is the only reliable and universally accepted travel document that provides proof that you are a citizen and have the right to enter Canada without being subjected to immigration screening. Make sure that the expiry date of the passport is well beyond your planned return date”.

Travelers were advised that the only valid documents to enter the country are “a valid Canadian passport, a Canadian temporary passport, or a Canadian emergency travel document”.

The government also noted that although the electronic travel authorisation system was put into effect earlier in 2016, it hasn’t been fully strictly enforced until now.

Visa-exempt foreign nationals, meanwhile, traveling to Canada have been shown leniency until the new system is fully online.

“A new entry requirement, known as an Electronic Travel Authorisation (eTA), is now in effect for visa-exempt foreign nationals traveling to or transiting through Canada by air. To make sure travelling to Canada stays easy and stress-free, leniency will be shown to travellers who are caught unawares until September 29, 2016.”

American-Canadian travelers will be exempt from the Canadian-passport-only rule and can enter Canada with a United States passport.

“American citizens, including American-Canadian citizens, must carry proper identification and meet the basic requirements to enter Canada. You do not need a Canadian passport, a Canadian visa or an eTA to fly to Canada if you are travelling with a valid US passport.”