On 15 January 2019, at the Office of the Council of Europe, Msgr. Paolo Rudelli, Holy See special envoy to the Council of Europe, deposited the instruments of accession of the Holy See, in the name and on behalf of Vatican City State, to the Convention of the Council of Europe on the Transfer of Sentenced Persons, of 21 March 1983, and to the Additional Protocol to the Convention on the Transfer of Sentenced Persons, of 18 December 1997. In the same act, Msgr. Rudelli deposited the instrument of ratification of the Holy See, in the name and on behalf of Vatican City State, for the Protocol Amending the Additional Protocol to the Convention on the Transfer of Sentenced Persons, of 22 November 2017. In expressing the consent of Vatican City State to be bound by these Treaties, the Holy See formulated six interpretative declarations, which form an integral part of the respective instruments of accession and ratification.

In accordance with Article 18, paragraph 3 of the Convention, and Article 4, paragraph 3 of the Additional Protocol of 1997, these two Agreements will enter into force for Vatican City State on 1 May 2019. The Protocol of Amendment of 2017 will instead enter into force once the conditions provided for in Article 4 of the same Protocol are fulfilled.