A plurilateral agreement is an agreement between more than two countries, but not a great many, which would be multilateral agreement.

Use of the term in the World Trade Organization

The term "plurilateral agreement" is used in the World Trade Organization

World Trade Organization

The World Trade Organization is an organization that intends to supervise and liberalize international trade. The organization officially commenced on January 1, 1995 under the Marrakech Agreement, replacing the General Agreement on Tariffs and Trade , which commenced in 1948...

. A plurilateral agreement implies that WTO member countries

WTO accession and membership

All World Trade Organization members have joined the organization as a result of negotiation, and membership consists of a balance of rights and obligations. The process of becoming a World Trade Organization member is unique to each applicant country, and the terms of accession are dependent upon...

 would be given the choice to agree to new rules on a voluntary basis. This contrasts with the multilateral WTO agreement, where all WTO members

WTO accession and membership

All World Trade Organization members have joined the organization as a result of negotiation, and membership consists of a balance of rights and obligations. The process of becoming a World Trade Organization member is unique to each applicant country, and the terms of accession are dependent upon...

 are party to the agreement. The Agreement on Government Procurement

Agreement on Government Procurement

The Agreement on Government Procurement is legally binding and plurilateral agreement in the World Trade Organization focusing on the subject of government and local government agencies procurement. The procurement in the Agreement includes goods, ranging from commodities to high technology...

 is typical plurilateral agreement.

Plurilateral treaties

A plurilateral treaty is a special type of multilateral treaty

Multilateral treaty

A multilateral treaty is a treaty to which three or more sovereign states are parties. Each party owes the same obligations to all other parties, except to the extent that they have stated reservations...

. A plurilateral treaty is a treaty between a limited number of states with a particular interest in the subject of the treaty. The primary difference between a plurilateral treaty and other multilateral treaties is that the availability of reservations

Reservation (law)

A reservation in international law is a caveat to a state's acceptance of a treaty. By the 1969 Vienna Convention on the Law of Treaties , a reservation is defined as a...

 is more limited under a plurilateral treaty. Due to the limited nature of a plurilateral treaty, the full cooperation of the parties to the treaty is required in order for the object of the treaty to be met. As a result, reservations to plurilateral treaties are not allowed without the consent of all other parties to the treaty. This principle is codified in international law

International law

Public international law concerns the structure and conduct of sovereign states; analogous entities, such as the Holy See; and intergovernmental organizations. To a lesser degree, international law also may affect multinational corporations and individuals, an impact increasingly evolving beyond...

 by article 20(2) of the Vienna Convention on the Law of Treaties

Vienna Convention on the Law of Treaties

The Vienna Convention on the Law of Treaties is a treaty concerning the international law on treaties between states. It was adopted on 22 May 1969 and opened for signature on 23 May 1969. The Convention entered into force on 27 January 1980. The VCLT has been ratified by 111 states as of November...

:

When it appears from the limited number of the negotiating states and the object and purpose of a treaty that the application of the treaty in its entirety between all the parties is an essential condition of the consent of each one to be bound by the treaty, a reservation requires acceptance by all the parties.