The symbiotic relationship between Canada and the United States is apparent by the fact that they are each other's largest trading partner. However, as a result of these long-standing commercial ties, cross-border disputes involving witnesses and documents on both sides of the 49th parallel are inevitable. To effectively litigate these disputes south of the border, U.S. attorneys need to familiarize themselves with the steps necessary to compel evidence from a witness residing in Canada.
In the event that a witness in Canada will not voluntarily provide the sought-after information, the assistance of a Canadian court will become necessary. This assistance is requested through a letter of request (also known as a letter rogatory). A letter of request is a formal request made by a U.S. (or other domestic) court of a Canadian (or other foreign) court to secure its assistance in gaining access to evidence outside of its jurisdiction. Surprisingly, there is no treaty governing the collection of evidence located in Canada for use in U.S. proceedings. As a result, letters of request are enforced solely based on the principles of international comity, mutual deference, and judicial respect and courtesy.
Therefore, successfully obtaining evidence in Canada for use in a U.S. proceeding is a two-step process. First, the letters of request must be issued by the U.S. court before which the litigation is pending. Second, the letters of request must be enforced by the Canadian court in the jurisdiction where the evidence is located.