The exchange of letters, signed by Switzerland on June 28, 2012 and by Canada on July 23, 2012, to the Canada – Switzerland Income and Capital Tax Treaty (1997), as amended by the 2010 protocol, entered into force on October 31, 2013 and generally applies from December 16, 2011.

The exchange of letters contains details information that needs to be supplied by a competent authority which is requesting information from the other competent authority under the provisions regarding a request for administrative assistance under the agreement. The taxpayer about whom information is required should be named and any other people who may have related information should be named in the request. This is chosen to prevent general fishing for information and to ensure that requests are particular.