Article 21 of the Protocol contains special retrospective effective date provisions for

paragraphs 2 through 8 of Article XXIX B and certain related provisions of the Protocol. Paragraphs 2 through 8 of Article XXIX B and the specified related provisions generally will take effect with respect to deaths occurring after the date on which the Protocol enters into force (i.e., the date on which the instruments of ratification are exchanged). However, the benefits of those provisions will also be available with respect to deaths occurring after November 10, 1988, provided that a claim for refund due as a result of these provisions is filed by the later of one year from the date on which the Protocol enters into force or the date on which the applicable period for filing such a claim expires under the domestic law of the Contracting State concerned. The general effective dates set forth in Article 21 of the Protocol otherwise apply.

It is unusual for the United States to agree to retrospective effective dates. In this case, however, the negotiators believed that retrospective application was not inappropriate, given the fact that the TAMRA provisions were the impetus for negotiation of the Protocol and that the negotiations commenced soon after the enactment of TAMRA. The United States has agreed to retrospective effective dates in certain other instances (e.g., in the case of the U.S.-Germany estate tax treaty). The retrospective effective dates apply reciprocally, so that they will benefit the estates of U.S. decedents as well as Canadian decedents.