Children under 16 need only present proof of U.S. citizenship. Nevertheless, it is recommended that identification for children be carried anyway.
Any person under 18 traveling alone requires a letter from a parent or guardian granting permission to travel to Canada. The letter must state the traveler's name and the duration of the trip.
A divorced parent who has or shares custody of a child should carry a copy of the custody document. An adult accompanying a child and who is not the child's parent or legal guardian should have written permission from the parents or guardians to supervise the child.
When traveling in a group of vehicles, parents or guardians should be in the same vehicle as their children when arriving at the border. CBSA personnel are looking for missing children and may question adults about children traveling with them.