It has been reported that the US Senate has referred the fifth protocol to the United States-Canada income tax treaty, which was signed on 21 September 2007, to the Committee on Foreign Relations.

The referral was made by unanimous consent on 13 March 2008, which was the same date that the President transmitted the protocol to the Senate for advice and consent.

Under normal US ratification procedures, the Committee on Foreign Relations will hold public hearings and vote on recommending the protocol to the full Senate for ratification. It was reported that the protocol was ratified by the Canadian Parliament on 14 December 2007.