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U.S. passport holders must now have specific documentation from their company when traveling to Canada on business. While this policy is not entirely new, the Canadian Border Service Agency is now strictly enforcing this requirement. For further details, click here.
Documents needed at the Canadian border
The Canadian Border Service Agency may deny entry for not having the below requirements:
Please Note: As per the Canadian Border Service Agency, it is recommended, though not required by law, that a letter with the above information be included from the Canadian company with whom the traveler is doing business.
CEN-TA Cross Border Services - Tax, Visas, Immigration