Holy See
Although the Holy See is sometimes metonymically referred to as the "Vatican", the Vatican City State was distinctively established with the Lateran Treaty (1929) between the Holy See and Italy to ensure the temporal, diplomatic, and spiritual independence of the Papacy. As such, ambassadors are officially accredited to the Holy See and not the Vatican City State. Conversely, Papal nuncios to states and international organisations are recognised as representing the Holy See and the integrity of the Catholic Church along with its 1.3 billion members, not the Vatican City State, as prescribed also in the Canon law of the Catholic Church (1983). The "Holy See" thus refers to the See of Rome viewed as the central government of the Catholic Church. The Catholic Church, in turn, is the largest non-government provider of education and health care in the world, while the diplomatic status of the Holy See facilitates the access of its vast international network of charities.
Vatican City
Vatican City issues its own coins and stamps. It has used the euro as its currency since 1 January 1999, owing to a special agreement with the European Union (council decision 1999/98). Euro coins and notes were introduced on 1 January 2002—the Vatican does not issue euro banknotes. Issuance of euro-denominated coins is strictly limited by treaty, though somewhat more than usual is allowed in a year in which there is a change in the papacy. Because of their rarity, Vatican euro coins are highly sought by collectors. Until the adoption of the Euro, Vatican coinage and stamps were denominated in their own Vatican lira currency, which was on par with the Italian lira.