Depositary State

A depositary is the custodian of a treaty. While the role is often filled by an international organization (such as the UN Secretary-General), many treaties designate one or more states to perform the function. The depositary's duties are codified in Articles 76–77 of the Vienna Convention on the Law of Treaties (1969) and include: keeping custody of the original text, preparing certified copies, receiving signatures and instruments of ratification or accession, examining whether such instruments are in due and proper form, registering the treaty with the UN Secretariat under Article 102 of the UN Charter, and notifying parties of reservations, objections, denunciations, and entry-into-force events.

The depositary's function is administrative and impartial, not political. Under VCLT Article 76(2), the depositary must act impartially even when a dispute arises between a party and the depositary itself over performance of its functions.

Prominent examples of state depositaries:

• Switzerland is depositary of the four Geneva Conventions of 1949 and their Additional Protocols.
• The United States, United Kingdom, and Russian Federation (as successor to the USSR) are the three co-depositaries of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT, 1968). This tri-depositary arrangement allowed states that did not recognize one another (e.g., the two Germanies, or states not recognizing certain governments) to deposit with whichever capital they recognized.
• The Netherlands is depositary of many Hague Conference on Private International Law conventions.
• Belgium serves as depositary of the North Atlantic Treaty (1949).

When a treaty has multiple depositary states, an instrument deposited with any one of them is generally sufficient. Disagreements between a state party and the depositary about the propriety of a notification are typically referred to the signatory states or the relevant organ of any organization concerned.