List of treaties by number of parties
General principles of ratification
In general, multilateral treaties are open to ratification by any state. Some treaties may also be ratified by supranational bodies, such as the European Union, and by other international organizations.
In practice, the depositary of a treaty will usually only recognise ratifications of the treaty that are performed by a state that is recognised as a state at international law. A state can be formally recognised as such by becoming a member of the United Nations; there are currently 193 member states of the United Nations. The only non-UN states that undoubtedly meet the standard of statehood are the Cook Islands and Niue, who have had their "full treaty-making capacity" recognised by the United Nations Secretariat. The Holy See—while not a state per se but an entity closely tied to the state of Vatican City—is also widely recognised as being able to legitimately ratify treaties and has been granted non-member observer state status by the UN General Assembly. Following the UNGA passing a resolution granting non-member observer state status to the State of Palestine, the UNSG has begun to recognize its right to ratify treaties. Ratifications performed by other states with more limited recognition—such as the Republic of China (Taiwan); Kosovo; Northern Cyprus; Somaliland; the Sahrawi Arab Democratic Republic (Western Sahara); South Ossetia; Abkhazia; Transnistria; and Nagorno-Karabakh—have usually not been recognised by treaty depositaries as states that can ratify treaties, although there are some exceptions to this general rule.
If a state party to a treaty denounces the treaty, the state (often after a certain period before the denunciation takes effect) is no longer a party to the treaty, although in some cases certain parts of the treaty may continue to apply.
Ratifications by defunct states
States change over time, and often a state that ratified a treaty will cease to exist. International law deals with this issue in two ways. First, it is possible for a state to be declared the successor state to the defunct state. In this situation, any ratifications performed by the defunct state are transferred to and attributed to the successor state. Examples of successor states are the Russian Federation (successor to the Soviet Union), Serbia (successor to Serbia and Montenegro), Belarus (successor to the Byelorussian SSR), Ukraine (successor to the Ukrainian SSR), and Tanzania (successor to Tanganyika). It is possible for a single state to be the successor state of multiple states, as with Yemen being the successor state of both North Yemen and South Yemen.
Second, some states have no legal successor state but cease to exist; in such cases, the ratifications performed by the state are disregarded. In some cases, such states are subsumed into an existing state, as when East Germany became part of the Federal Republic of Germany. In other cases, the defunct state is divided into two or more states, with none of the states being designated as the formal successor state. Examples of the latter situation include SFR Yugoslavia and Czechoslovakia. In this situation, the new states usually declare which treaties the defunct state ratified continue to have force for the new state. Such a declaration is regarded as a "ratification" by the new state.
For purposes of the numbers in this list, only ratifications, accessions, or successions of currently existing states are considered. No regard is given to ratifications by defunct states that have no current successor state.
Maximum limits to ratification numbers?
Due to these limitations, in 2016, the maximum number of state ratifications that a multilateral treaty can have is usually going to be 197; this total consists of all 193 UN member states; both UN observers, the Holy See and State of Palestine; and the Cook Islands and Niue. If supranational or other international organizations ratify the treaty, the total number of ratifications may exceed 197.
Legal effect of a high number of ratifications
When a treaty is ratified by nearly all recognised states in the world, the legal principles contained in the treaty may become customary international law. Customary international law applies to all states, whether or not the state has ratified a treaty that enshrines the principle. There is no set number of ratifications that are required to convert a treaty's principles into customary international law, and states and experts often disagree on what principles have and have not attained the status.
List of treaties by number of parties
Below is the list of treaties by number of parties. Only treaties with a minimum of 170 parties are included.
- For simplicity, this article uses "ratify" to mean "ratify, accedes to, approves, or succeeds to".
- For simplicity, this article treats the Holy See as a state rather than as a non-state organization.
- Similar declarations may be made by states that result from the division of a defunct state when there is a formal successor state. For instance, when Serbia and Montenegro divided into Serbia and Montenegro, Serbia was designated as the successor state. Upon division, Montenegro made declarations as to which treaties ratified by Serbia and Monenegro remain in force for Montenegro.
- Total number of UN member states that are party to the treaty.
- Total number of non–UN member states that are party to the treaty.
- Total number of states that are party to the treaty.
- Total number of non-states, such as supranational or other international organizations, that are party to the treaty.
- Total number of parties to the treaty.
- Identity of the states that are not parties to the treaty that could become party to the treaty (including states that have denounced the treaty)
- The London, Copenhagen, Montreal and Beijing Amendments have also been ratified by all 197 parties.
- By its Geneva Conventions Act 1958, Niue considers New Zealand's ratification of the Geneva Conventions to cover its territory.
- Ratified the treaty but has subsequently denounced it and withdrawn.
- Switzerland made the following declaration upon ratification: "My Government has instructed me to notify you that the authorities in Switzerland have agreed with the authorities in the Principality of Liechtenstein that this Convention will be applicable to the territory of the Principality as well as to that of the Swiss Confederation, as long as the Treaty of 29 March 1923 integrating the whole territory of Liechtenstein with the Swiss customs territory will remain in force".
- Not including North Korea, which ratified the treaty but subsequently denounced it. There is disagreement among the parties to the treaty whether North Korea's withdrawal was in conformity with the terms of the treaty.
- The UPU recognises the membership of 192 parties. From 1874 to 1964, membership in the Universal Postal Union was governed by the Treaty of Bern. On 10 July 1964, the UPU incorporated the Treaty of Bern into a new Constitution of the UPU, which is now the governing treaty that is ratified when a state joins the UPU. Include as UPU members are two "joint memberships" for dependent territories (one for the British overseas territories and one for the Caribbean constituent countries (Dutch: landen) of the Kingdom of the Netherlands (Aruba, Curaçao and Sint Maarten), originally as Netherlands Antilles). Dependent territories are not permitted to ratify the UPU Constitution, but because the Treaty of Bern allowed for dependencies to join the UPU, listing these members separately as "Colonies, Protectorates, etc.", the Constitution of the Universal Postal Union grandfathered them when membership was restricted to sovereign states. However, neither the British nor the Dutch entities ratified the Treaty of Bern separate from the ratifications of the United Kingdom and the Kingdom of the Netherlands, respectively. Also included as members are three states which were party to the Treaty of Bern in 1964, and hence members of the UPU, and which have signed but never ratified the Constitution: Dominican Republic, Honduras, Sudan. These states are deemed to have "tacitly ratified" the agreement due to their continued participation in the UPU.
- The Constitution of the ILO was originally part of the 1919 Treaty of Versailles. Since 1919, the Constitution has been amended a number of times, most significantly in 1945–46, when the ILO became a specialized agency of the United Nations.
- Prior to ratifying this treaty, the state would have to ratify the Articles of Agreement of the International Bank for Reconstruction and Development, since only IBRD member states may ratify this agreement.
- An amendment allowing accession by regional organizations and customs territories has not entered into force
- The depositary (Government of Belgium) has registered 179 parties, as it includes the dependent territories of Bermuda, Netherlands Antilles, Hong Kong, and Macau.
- North Korea ratified the IAEA Statute in 1974, but denounced it 1994.
- "Historical Information". United Nations. Retrieved 2014-04-10.
- "Organs Supplement", Repertory of Practice (PDF), UN, p. 10, archived from the original (PDF) on 2013-10-19, retrieved 2014-04-10
- "Non-member States". United Nations. Retrieved 2014-04-10.
- "TREATIES DEPOSITED WITH THE SECRETARY-GENERAL CLOSE TO UNIVERSAL PARTICIPATION" (PDF). United Nations. 2016-05-27. Retrieved 2016-09-08.
- Vienna Convention for the Protection of the Ozone Layer: Treaty status.
- Montreal Protocol: Treaty status.
- UN Framework Convention on Climate Change: Treaty status.
- UN Convention to Combat Desertification: Treaty status.
- "Conventions de Genève pour la protection des victimes de la guerre: Convention pour l'amélioration du sort des blessés et des malades dans les forces armées en campagne" (PDF) (in French). Federal Department of Foreign Affairs of Switzerland. Retrieved 2014-10-14.
- "Conventions de Genève pour la protection des victimes de la guerre: Convention pour l'amélioration du sort des blessés, des malades et des naufragés des forces armées sur mer" (PDF) (in French). Federal Department of Foreign Affairs of Switzerland. Retrieved 2014-10-14.
- "Conventions de Genève pour la protection des victimes de la guerre: Convention relative au traitement des prisonniers de guerre" (PDF) (in French). Federal Department of Foreign Affairs of Switzerland. Retrieved 2014-10-14.
- "Conventions de Genève pour la protection des victimes de la guerre: Convention relative à la protection des personnes civiles en temps de guerre" (PDF) (in French). Federal Department of Foreign Affairs of Switzerland. Retrieved 2014-10-14.
- Convention on the Rights of the Child: Treaty status.
- Convention on Biological Diversity: Treaty status.
- Constitution of the United Nations Educational, Scientific and Cultural Organisation: Treaty status.
- Constitution of the Food and Agriculture Organization: Treaty status.
- Constitution of the World Health Organization: Treaty status.
- United Nations Charter: Treaty status.
- ITU member states.
- In 1992, the Constitution and Convention of the International Telecommunication Union replaced and succeeded the 1865 International Telegraph Convention as the founding document of the ITU.
- Convention concerning the Protection of the World Cultural and Natural Heritage: Treaty status.
- Chemical Weapons Convention: Treaty status.
- Kyoto Protocol: Treaty status.
- Chicago Convention on International Civil Aviation: Treaty status.
- Vienna Convention on Diplomatic Relations: Treaty status Archived 2010-12-27 at the Wayback Machine.
- WIPO Convention: Treaty status.
- Treaty on the Non-Proliferation of Nuclear Weapons: Treaty status.
- "Democratic People's Republic of Korea: Accession to Treaty on the Non-Proliferation of Nuclear Weapons (NPT)". United Nations Office for Disarmament Affairs. Retrieved 2013-03-01.
- UN Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances: Treaty status.
- Convention on the Elimination of All Forms of Discrimination against Women: Treaty status.
- IBRD Members.
- United Nations Convention against Transnational Organized Crime: Treaty status.
- International Monetary Fund: List of members.
- Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation: Treaty status.
- International Convention for the Suppression of the Financing of Terrorism: Treaty status.
- "List of member countries of the Universal Postal Union" (PDF). Universal Postal Union. 2014-07-31. Retrieved 2014-10-14.
- Universal Postal Union: Member countries.
- "Constitution General Regulations" (PDF). Universal Postal Union. 2010. pp. XII.
- "Universal Postal Convention". Universal Postal Union. 1952-07-11. Retrieved 2012-08-11.
- "Constitution of the Universal Postal Union". Universal Postal Union. 1964-07-10. Retrieved 2012-08-11.
- International Labour Organization: Member states.
- International Convention against Doping in Sport: Treaty status.
- Basel Convention: Treaty status Archived 2012-09-09 at the Wayback Machine.
- Tokyo Convention: Treaty status.
- Single Convention on Narcotic Drugs: Treaty status.
- Paris Agreement: Treaty status
- United Nations Convention against Corruption: Treaty status.
- Hague Hijacking Convention: Treaty status.
- International Finance Corporation: Members.
- Convention on Psychotropic Substances: Treaty status.
- Convention on International Trade in Endangered Species of Wild Fauna and Flora: Member countries.
- International Plant Protection Convention: Treaty status.
- Biological Weapons Convention: Treaty status.
- Ratifications of C182 – Worst Forms of Child Labour Convention, 1999 (No. 182).
- Stockholm Convention: Status of ratifications.
- Multilateral Investment Guarantee Agency: Members.
- WHO Framework Convention on Tobacco Control: Treaty status.
- Vienna Convention on Consular Relations: Treaty status.
- Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons, including Diplomatic Agents: Treaty status.
- International Convention on the Elimination of All Forms of Racial Discrimination: Treaty status Archived 2011-02-11 at the Wayback Machine.
- Ratifications of C029 – Forced Labour Convention, 1930 (No. 29).
- Convention for the Safeguarding of the Intangible Cultural Heritage: Treaty status.
- UN Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons, including Diplomatic Agents: Treaty status.
- Paris Convention for the Protection of Industrial Property: Treaty status.
- Convention on the Rights of Persons with Disabilities: Treaty status.
- Agreement establishing the International Fund for Agricultural Development: Treaty status.
- International Convention against the Taking of Hostages: Treaty status.
- Berne Convention for the Protection of Literary and Artistic Works: Treaty status.
- Convention establishing a Customs Co-operation Council: Treaty status.
- Convention portant création d'un conseil de coopération douanière et annexe, faites à Bruxelles le 15 Décembre 1950.
- Protocol for the Suppression of Unlawful Acts of Violence at Airports serving International Civil Aviation: Treaty status.
- Ratifications of C111 - Discrimination (Employment and Occupation) Convention, 1958 (No. 111).
- Optional Protocol to the Convention on the Rights of the Child on the Sale of Children, Child Prostitution and Child Pornography: Treaty status.
- "Protocole additionnel aux Conventions de Genève du 12 août 1949 relatif à la protection des victimes des conflits armés internationaux (Protocole I)" (PDF) (in French). Federal Department of Foreign Affairs of Switzerland. Retrieved 2014-10-14.
- Convention on the International Maritime Organization: Treaty status.
- International Maritime Organization: Member states.
- International Development Association: Members.
- Ratifications of C105 – Abolition of Forced Labour Convention, 1957 (No. 105).
- Ratifications of C100 - Equal Remuneration Convention, 1951 (No. 100).
- Protocol to Prevent, Suppress and Punish Trafficking in Persons, Especially Women and Children: Treaty status.
- International Covenant on Civil and Political Rights: Treaty Status
- "List of Member States". International Atomic Energy Agency. 2018-04-30. Retrieved 2018-05-22.
- Cartagena Protocol on Biosafety: Treaty status Archived 2014-03-05 at the Wayback Machine.
- Ramsar Convention: Treaty status
- [https://treaties.un.org/Pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XVIII-9&chapter=18&lang=en International Convention for the Suppression of Terrorist Bombings: Treaty Status