View source for Currency union

{{Short description|Agreement involving states sharing a single currency}}{{trade bloc}}
[[File:Currency union.PNG|thumb|right|300px|World map of current international currency unions:
{{legend|#0000FF|EUR [[Euro]]}}
{{legend|#00FF00|USD [[United States dollar]]}}
{{legend|#FF3800|CHF [[Swiss franc]]}}
{{legend|#B803FF|INR [[Indian rupee]]}}
{{legend|#FF00FF|AUD [[Australian dollar]]}}
{{legend|#000000|XCD [[Eastern Caribbean dollar]]}}
{{legend|#FF8413|ZAR [[South African rand]]}}
{{legend|#00FFFF|XOF [[West African CFA franc]]}}
{{legend|#30D5C8|XAF [[Central African CFA franc]]}}
{{legend|#7B3F00|XPF [[CFP franc]]}}]]
A '''currency union''' (also known as '''monetary union''') is an intergovernmental agreement that involves two or more [[State (polity)|states]] sharing the same [[currency]]. These states may not necessarily have any [[Economic integration#Stages|further integration]] (such as an [[economic and monetary union]], which would have, in addition, a [[customs union]] and a [[single market]]).

There are three types of currency unions:
* ''Informal'' – unilateral adoption of a [[foreign currency]].<ref>{{cite web |title=World Bank |url=http://siteresources.worldbank.org/PGLP/Resources/Session9.pdf |website=WorldBank.org |access-date=30 April 2019}}</ref>
* ''Formal'' – adoption of [[foreign currency]] by virtue of bilateral or multilateral agreement with the [[monetary authority]], sometimes supplemented by issue of local currency in [[currency peg]] regime.
* ''Formal with common policy'' – establishment by multiple countries of a common [[monetary policy]] and [[monetary authority]] for their common currency.

The theory of the [[optimal currency area]] addresses the question of how to determine what geographical regions should share a currency in order to maximize economic efficiency.<ref>{{cite web |title=The Optimum Currency Area Theory and the EMU |url=https://www.intereconomics.eu/contents/year/2013/number/5/article/the-optimum-currency-area-theory-and-the-emu.html |website=Intereconomics |last1=Hafner |first1=Kurt A. |last2=Jager |first2=Jennifer |access-date=1 April 2021}}</ref>

==Advantages and disadvantages==
{{More citations needed section|date=August 2019}}
Implementing a new currency in a country is always a controversial topic because it has both many advantages and disadvantages. New currency has different impacts on businesses and individuals, which creates more points of view on the usefulness of currency unions. As a consequence, governmental institutions often struggle when they try to implement a new currency, for example by entering a currency union.

===Advantages===
*A currency union helps its members strengthen their competitiveness on a global scale and eliminate the exchange rate risk.
*Transactions among member states can be processed faster and their costs decrease since fees to banks are lower.<ref>{{cite web |last1=Global Economy |first1=The |title=Currency unions, Monetary unions |url=https://www.theglobaleconomy.com/guide/article/21/ |website=The Global Economy |publisher=Naven Valev |access-date=1 April 2021}}</ref>
*Prices are more transparent and so are easier to compare, which enables fair competition.
*The probability of a monetary crisis is lower. The more countries there are in the currency union, the more they are resistant to crisis.

===Disadvantages===
*The member states lose their sovereignty in monetary policy decisions. There is usually an institution (such as a central bank) that takes care of the monetary policymaking in the whole currency union.
*The risk of asymmetric "shocks" may occur. The criteria set by the currency union are never perfect, so a group of countries might be substantially worse off while the others are booming.
*Implementing a new currency causes high financial costs. Businesses and also single persons have to adapt to the new currency in their country, which includes costs for the businesses to prepare their management, employees, and they also need to inform their clients and process plenty of new data.
*Unlimited capital movement may cause moving most resources to the more productive regions at the expense of the less productive regions. The more productive regions tend to attract more capital in goods and services, which might avoid the less productive regions.<ref>{{cite web |title=Study |url=https://study.com/academy/lesson/currency-union-definition-pros-cons.html |website=Study.com |access-date=30 April 2019}}</ref><ref>{{cite web |title=Global Financial Integrity |url=https://www.gfintegrity.org/asymmetric-shocks-and-other-woes-of-the-eurozone/ |website=gfintegrity.org |date=20 June 2011 |access-date=30 April 2019}}</ref>

==Convergence and divergence==
'''Convergence''' in terms of [[macroeconomics]] means that countries have a similar economic behaviour (similar [[inflation rates]] and [[economic growth]]).
It is easier to form a currency union for countries with more convergence as these countries have the same or at least very similar goals. The [[European Monetary Union]] (EMU) is a contemporary model for forming currency unions. Membership in the EMU requires that countries follow a strictly defined set of criteria (the member states are required to have a specific rate of inflation, [[government deficit]], [[government debt]], long-term [[interest rates]] and [[exchange rate]]). Many other unions have adopted the view that convergence is necessary, so they now follow similar rules to aim the same direction.

'''Divergence''' is the exact opposite of convergence. Countries with different goals are very difficult to integrate in a single currency union. Their economic behaviour is completely different, which may lead to disagreements. Divergence is therefore not optimal for forming a currency union.<ref>{{cite web |last1=Enoch |first1=Charles |last2=Krueger |first2=Russell |title=Currency unions: key variables, definitions, measurement, and statistical improvement |url=https://www.bis.org/ifc/publ/ifcb32j.pdf |website=Bank for International Settlements |access-date=30 April 2019}}</ref>

==History==
The first currency unions were established in the 19th century. The German [[Zollverein]] came into existence in 1834, and by 1866, it included most of the German states. The fragmented states of the German Confederation agreed on common policies to increase trade and political unity.

The [[Latin Monetary Union]], comprising France, Belgium, Italy, Switzerland, and Greece, existed between 1865 and 1927, with coinage made of [[gold]] and [[silver]]. Coins of each country were legal tender and freely interchangeable across the area. The union's success made other states join informally.

The [[Scandinavian Monetary Union]], comprising Sweden, Denmark, and Norway, existed between 1873 and 1905 and used a currency based on gold. The system was dissolved by Sweden in 1924.<ref>{{cite news |title=History of currency unions |url=https://www.theguardian.com/world/2001/dec/10/euro.eu |website=The Guardian |date=10 December 2001 |access-date=30 April 2019 |last1=Bolton |first1=Sally }}</ref>

A currency union among the British colonies and protectorates in Southeast Asia, namely the Federation of Malaya, North Borneo, Sarawak, Singapore and Brunei was established in 1952. The Malaya and British Borneo dollar, the common currency for circulation was issued by the [[Board of Commissioners of Currency, Malaya and British Borneo]] from 1953 until 1967. Following the cessation of the common currency arrangement, Malaysia (the combination of Federation of Malaya, North Borneo, Sarawak), Singapore and Brunei began issuing their own currencies. Contemporarily, a currency reunion of these countries might still be feasible based on the findings of economic convergence.<ref>{{cite web
 |url         = http://moneymuseum.bnm.gov.my/index.php?ch=8&pg=14&ac=38
 |title       = History of Money in Malaysia: Colonial Notes & Coins
 |access-date  = 5 July 2021
 |date        = 2010
 |publisher   = Bank Negara Malaysia
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20110722233307/http://moneymuseum.bnm.gov.my/index.php?ch=8&pg=14&ac=38
 |archive-date = 22 July 2011
 |df          = dmy-all
}}</ref><ref>{{cite journal|title=Economic Feasibility of Malaysia and Singapore-Brunei Monetary Reunion: A Scrutiny during Major Financial Crises|first1=C. H.|last1=Quah|first2=Y. J.|last2=Ho|date=2020|journal=Applied Economics Journal|volume=27|issue=1|pages=23–51|url=https://so01.tci-thaijo.org/index.php/AEJ/article/view/222909/163771}}</ref>

==List of currency unions==
===Existing===
{{clr}}
{| class="wikitable sortable"
|-
! Currency
! Union
! Users 
! Est.
! Status
! data-sort-type=number | Population
|-
|[[CFA franc]]
|''Issued by the ([[France|French]]) [[Institut d'émission d'outre-mer|Overseas Issuing Institute]]'' between 1945 and 1962 then by the [[Central Bank of West African States]] and the [[Bank of Central African States]]
|''[[West African CFA franc]] users:''<br/>
''{{flag|Benin}}''<br />
''{{flag|Burkina Faso}}''<br />
''{{flag|Côte d'Ivoire}}''<br />
''{{flag|Guinea-Bissau}}''<br />
''{{flag|Mali}}''<br />
''{{flag|Niger}}''<br />
''{{flag|Senegal}}''<br />
''{{flag|Togo}}''
----
''[[Central African CFA franc]] users:''<br />
''{{flag|Cameroon}}''<br />
''{{flag|Central African Republic}}''<br />
''{{flag|Chad}}''<br />
''{{flag|Equatorial Guinea}}''<br />
''{{flag|Gabon}}''<br />
''{{flag|Republic of the Congo}}''
|1945
|Formal, common policy
|151,978,440
|-
|[[CFP franc]]
|''Issued by the ([[France|French]]) [[Institut d'émission d'outre-mer|Overseas Issuing Institute]]''
|''{{flag|French Polynesia}}''<br />
''{{flag|New Caledonia|local}}''<br />
''{{flag|Wallis and Futuna|local}}''
|1945
|Formal, common policy
|552,537
|-
|[[Eastern Caribbean dollar]]
|[[Eastern Caribbean Currency Union]] of the [[Eastern Caribbean Central Bank]] (ECCB) and the [[Organisation of Eastern Caribbean States|OECS]].
|''{{flag|Anguilla}}''<br />
''{{flag|Antigua and Barbuda}}''<br />
''{{flag|Dominica}}''<br />
''{{flag|Grenada}}''<br />
''{{flag|Montserrat}}''<br />
''{{flag|Saint Kitts and Nevis}}''<br />
''{{flag|Saint Lucia}}''<br />
''{{flag|Saint Vincent and the Grenadines}}''
|1965
|Formal, common policy<br />''de facto'' [[economic and monetary union|EMU]] for [[CARICOM Single Market and Economy|CSME]] members<ref>[[Anguilla]] and [[Montserrat]] are members of OECS currency union, but not of the CSME.</ref>
|625,000
|-
|[[Euro]]
|[[International status and usage of the euro]]
|{{flagicon|European Union}} [[Eurozone]]:<br/>
{{flag|Austria}}<br/>
{{flag|Belgium}}<br/>
{{flag|Croatia}}<br/>
{{flag|Cyprus}}<br/>
{{flag|Estonia}}<br/>
{{flag|Finland}}<br/>
{{flag|France}}<br/>
{{flag|Germany}}<br/>
{{flag|Greece}}<br/>
{{flag|Ireland}}<br/>
{{flag|Italy}}<br/>
{{flag|Latvia}}<br/>
{{flag|Lithuania}}<br/>
{{flag|Luxembourg}}<br/>
{{flag|Malta}}<br/>
{{flag|Netherlands}}<br/>
{{flag|Portugal}}<br/>
{{flag|Slovakia}}<br/>
{{flag|Slovenia}}<br/>
{{flag|Spain}}<br/>
----
''and [[special member state territories and the European Union|EU special territories]]:''<br/>
''{{flag|French Southern and Antarctic Lands}}''<br/>
''{{flag|Saint Barthélemy|local}}''<br/>
''{{flag|Saint Pierre and Miquelon|local}}''
----
''{{flag|Akrotiri and Dhekelia}}''<br/>
{{flag|Andorra}}<br />
{{flag|Kosovo}}<br />
{{flag|Monaco}}<br />
{{flag|Montenegro}}<br />
{{flag|San Marino}}<br />
{{flag|Vatican City}}
|1999/2002
|Formal, common policy and [[economic and monetary union|EMU]] for EU members<br>Formal for Monaco and Akrotiri and Dhekelia (which form part of the EU's customs territory)<br>Informal for Kosovo, Montenegro<br>Formal for Andorra and San Marino (which are in customs union with the EU's customs territory)
|341,008,867
|- 
|[[Singapore dollar]]<br />
[[Brunei dollar]]
|''Managed together by the [[Monetary Authority of Singapore]]''
|{{flag|Brunei}}<br />
{{flag|Singapore}}
|1967
|Formal; currencies mutually exchangeable<ref>To all intents and purposes a monetary union. They are the last two nations whose dollars have remained at par and mutually interchangeable since the days when the [[Spanish Dollar]] was the united currency of large areas of the [[New World]] and [[Southeast Asia]].</ref>
|5,137,000
|-
|[[Australian dollar]]
|
|{{flag|Australia}}<br/>
----
and ''[[Australian External Territories|external territories]]:''<br/>
''{{flag|Ashmore and Cartier Islands}}''<br/>
''{{flag|Australian Antarctic Territory}}''<br/>
''{{flag|Christmas Island}}''<br/>
''{{flag|Cocos (Keeling) Islands}}''<br/>
''{{flag|Coral Sea Islands|name=Coral Sea Islands Territory}}''<br/>
''{{flag|Heard Island and McDonald Islands}}''<br/>
''{{flag|Norfolk Island}}''
----
{{flag|Kiribati}}<br />
{{flag|Nauru}}<br />
{{flag|Tuvalu}}
|1966
|Informal
|24,557,000
|-
|[[Pound sterling]]
|[[Sterling area]] (former)
|{{flag|United Kingdom}}<br />
----
''and [[British Overseas Territories|Overseas Territories]]:''<br/>
''{{flag|British Antarctic Territory}}''<br/>
''{{flag|British Indian Ocean Territory}}''<br/>
''{{flag|Falkland Islands}}''<br/>
''{{flag|Gibraltar}}''<br/>
''{{flag|Saint Helena, Ascension and Tristan da Cunha}}''<br/>
''{{flag|South Georgia and the South Sandwich Islands}}''
----
''and [[Crown Dependencies]]:''<br/>
''{{flag|Bailiwick of Guernsey}}''<br/>
''{{flag|Jersey|name=Bailiwick of Jersey}}''<br/>
''{{flag|Isle of Man}}''
|1939
|Semi-formal. UK banknotes are legal tender in locations outside the UK.  Local currencies are pegged to the GBP but not necessarily accepted in the UK: [[Guernsey pound]], [[Manx pound]], [[Jersey pound]] and [[Alderney pound]], [[Falkland Islands pound]], [[Gibraltar pound]], [[Saint Helena pound]]
|62,321,000
|-
|[[Indian rupee]]
|
|{{flag|India}}<br />
{{flag|Bhutan}}<ref>alongside the [[Bhutanese ngultrum|ngultrum]]</ref><br />
{{flag|Nepal}}<ref><!--[[Nepalese rupee]] pegged to it (₹1 = रू1.6 NPR). -->Not official, but freely used as a tender in Nepal, due to primarily the economic flux with India and also the instability caused by that country's civil war.</ref>
|1974
|Informal<br />
Nepal minor usage
|1,352,000,000
|-
|[[New Zealand dollar]]
|
|{{flag|New Zealand}}<br>
----
''and [[Realm of New Zealand|Realm]]:''<br>
''{{flag|Cook Islands}}''<br>
''{{flag|Niue}}''<br>
''{{flag|Tokelau}}''<br>
----
''{{flag|Pitcairn Islands}}''
|1967
|Informal
|4,411,000
|-
|[[Israeli new sheqel]]
|
|{{flag|Israel}}<br />
{{flag|Palestine}}
|1927/1986
|Informal
|11,738,000
|-
|[[Jordanian dinar]]<ref>{{Cite news| issn = 0190-8286| last = Zacharia| first = Janine| title = Palestinian officials think about replacing Israeli shekel with Palestine pound| journal = The Washington Post and Times-Herald| access-date = 2018-08-22| date = 2010-05-31| url = https://www.washingtonpost.com/wp-dyn/content/article/2010/05/29/AR2010052903131.html}}</ref><ref>{{Cite book| publisher = Routledge| isbn = 9780415327619|editor= David Cobham| last = Cobham| first = David| title = The Economics of Palestine: Economic Policy and Institutional Reform for a Viable Palestine State| chapter = Alternative currency arrangements for a new Palestinian state| location = London| date = 2004-09-15 |chapter-url=http://fmwww.bc.edu/repec/mmfc04/13.pdf| access-date = 2018-08-22}}</ref><!-- see talk. What is the "official" currency? For example does the PNA government accept payments of local taxes in Jordanian dinar/USD/EUR/etc. or only in Israeli shekes? -->
|
|{{flag|Jordan}}<br />
{{flag|Palestine}} ([[West Bank]] only)
|
|Informal
|8,922,000
|-
|[[Russian ruble]]
|
|{{flag|Russia}}<br />
{{flag|Abkhazia}}<br />
{{flag|South Ossetia}}<br />
 
|2008
|Informal
|142,177,000
|-
|[[South African rand]]
|[[Common Monetary Area|Multilateral Monetary Area]]
|{{flag|Lesotho}}<br />
{{flag|Namibia}}<br />
{{flag|South Africa}}<br />
{{flag|Eswatini}}
|1974
|Formal<br />''de facto'' [[customs and monetary union]] for the [[Southern African Customs Union|SACU]] member countries
|52,924,669
|-
|[[Swiss franc]]
|
|{{flag|Liechtenstein}}<br />
{{flag|Switzerland}}
|1920
|Informal<br>''de facto'' [[economic and monetary union]]—1924 creation of a [[customs union]], then members of the [[European Free Trade Association]] (a [[single market|common market]]), and now also part of the [[European Single Market]].
|8,547,015
|-
|[[Turkish lira]]
|
|{{flag|Turkey}}<br />
{{flag|Turkish Republic of Northern Cyprus}}
|1983
|Informal
|75,081,100
|-
|[[United States dollar]]
|
|{{flag|United States}}<br />
----
and ''[[insular area]]s:''<br />
''{{flag|American Samoa}}''<br />
''{{flag|Guam}}''<br />
''{{flag|United States Minor Outlying Islands}}''<br />
''{{flag|Northern Mariana Islands}}''<br />
''{{flag|Puerto Rico}}''<br />
''{{flag|United States Virgin Islands}}''
----
and ''[[Compact of Free Association]] members'':<br />
{{flag|Marshall Islands}}<br />
{{flag|Federated States of Micronesia|Micronesia}}<br />
{{flag|Palau}}<br />
----
{{flag|Ecuador}}<br>
{{flag|El Salvador}}<br>
{{flag|Panama}}<br>
{{flag|Timor-Leste}}<br />
''{{flag|Turks and Caicos Islands}}''<br />
''{{flag|British Virgin Islands}}''<br />
{{flagicon|Netherlands}} [[Caribbean Netherlands|BES islands]]<br />
|1904<br />
(Panama only)
|Formal for insular areas and sovereign status with [[Compact of Free Association]],<ref>{{cite web|url=http://www.fsmlaw.org/compact/t02art05.htm|title=Compact- Title 02 Article 05|website=www.fsmlaw.org}}</ref> informal for other areas
|339,300,000
|}

Note: Every [[customs and monetary union]] and [[economic and monetary union]] also has a currency union.

{{flag|Zimbabwe}} is theoretically in a currency union with four blocs as the South African rand, [[Botswana pula]], British pound and US dollar freely circulate. The US Dollar was, until 2016, official tender.<ref>{{Cite news|url=http://news.bbc.co.uk/2/hi/africa/7859033.stm|title=Zimbabwe abandons its currency|date=2009-01-29|access-date=2019-10-15|language=en-GB}}</ref>

Additionally, the [[list of autonomous areas by country|autonomous]] and [[dependent territory|dependent]] territories, such as some of the [[special member state territories and the European Union|EU member state special territories]], are sometimes treated as separate [[customs territory]] from their mainland state or have varying arrangements of formal or de facto [[customs union]], [[single market|common market]] and currency union (or combinations thereof) with the mainland and in regards to third countries through the [[trade agreement|trade pacts]] signed by the mainland state.<ref>EU [[Overseas Countries and Territories|Overseas countries]] and some other territories participate partially in the EU single market per [http://eur-lex.europa.eu/en/treaties/dat/12002E/htm/C_2002325EN.003301.html part four of the Treaty Establishing the European Community] {{Webarchive|url=https://web.archive.org/web/20131116105433/http://eur-lex.europa.eu/en/treaties/dat/12002E/htm/C_2002325EN.003301.html |date=2013-11-16 }}; Some EU Outermost regions and other territories use the [[Euro]] of the currency union, others are part of the [[European Union Customs Union|customs union]]; some participate in both unions and some in neither.<br />[[Territories of the United States]], [[Australian External Territories]] and [[Realm of New Zealand]] territories share the currency and mostly also the [[single market|market]] of their respective mainland state, but are generally not part of its [[customs territory]].</ref>

====Currency union in Europe====
The European currency union is a part of the [[Economic and Monetary Union of the European Union]] (EMU). EMU was formed during the second half of the 20th century after historic agreements, such as [[Treaty of Paris (1951)]], [[Maastricht Treaty]] (1992). In 2002, the [[euro]], a single European currency, was adopted by 12 member states. Currently, the [[Eurozone]] has 20 member states. The other members of the European Union are required to adopt the euro as their currency (except for Denmark, which has been given the right to opt out), but there has not been a specific date set. The main independent institution responsible for stability of the euro is the [[European Central Bank]] (ECB). Together with 15 national banks it forms the European System of Central Banks. The Governing Board consists of the Executive Committee of the ECB and the governors of individual national banks, and determines the monetary policy, as well as short-term monetary objectives, key interest rates and the extent of monetary reserves.<ref>{{cite web |title=European Union |url=https://ec.europa.eu/info/business-economy-euro/economic-and-fiscal-policy-coordination/economic-and-monetary-union_en |website=Europa.eu |access-date=30 April 2019}}</ref>

===Planned===
{{see also|List of proposed currencies}}
{| class="wikitable sortable"
|-
! Community
! Currency
! Region
! Target date
! width=30%| Notes
|-
|{{Flagicon|East African Community}} [[East African Community]]
| [[East African shilling#Second East African shilling|East African shilling]]
| Africa
| 2012 (not met), 2015 (not met), 2024<ref name=":0">{{Cite journal|last1=Asongu|first1=Simplice|last2=Nwachukwu|first2=Jacinta|last3=Tchamyou|first3=Vanessa|date=2016-08-01|title=A Literature Survey on Proposed African Monetary Unions|journal=Journal of Economic Surveys|volume=31|issue=3|language=en|pages=878–902|doi=10.1111/joes.12174|s2cid=38454408 |issn=1467-6419|url=http://www.afridev.org/RePEc/agd/agd-wpaper/A-Literature-Survey-on-Proposed-African-Monetary-Unions.pdf}}</ref>
|
|-
| [[West African Monetary Zone]]
| [[Eco (currency)|Eco]]
| Africa<!---these are broad regions to help the sort function-->
| 2027
| Inside [[Economic Community of West African States]], planned to eventually merge with [[West African CFA franc|West African franc]]
|-
| [[ASEAN+3]]
| [[Asian Monetary Unit]] {{citation needed|date=June 2016}}
| Asia<!---these are broad regions to help the sort function-->
| ?
| a [[free trade agreements]] matrix partially established
|-
|{{Flagicon image|GCC Flag.svg}} [[Cooperation Council for the Arab States of the Gulf]]
| [[Khaleeji (currency)|Khaleeji]]
| Arabian Peninsula
| ?
| [[Oman]] and the [[United Arab Emirates]] do not intend to adopt the currency at first but will do at a later date.
|-
|{{Flagicon image|Flag of the African Union.svg}} [[African Economic Community]]
| [[Afro (currency)|Afro or Afriq]]
| Africa
| 2028<ref>{{Cite web|url=https://www.brookings.edu/blog/africa-in-focus/2014/01/09/will-there-be-an-african-economic-community|title= A common currency at a later stage of Africa's economic integration|date= 30 November 2001}}</ref>
| Planned for 2028 or later
|-
|Brazil, Argentina and possibly other countries
|Sur
|Latin America
| ?
|As Financial Times reports, Brazil and Argentina will announce in January 2023 that they are starting preparatory work on a common currency "Sur" (South). The initiative would later be extended to invite other Latin American nations.<ref>{{Cite news |date=2023-01-22 |title=Brazil and Argentina to begin preparations for common currency, Financial Times reports |language=en |work=Reuters |url=https://www.reuters.com/markets/currencies/brazil-argentina-begin-preparations-common-currency-ft-2023-01-22/ |access-date=2023-01-22}}</ref>
|}

===Disbanded===
{{See also|Bretton Woods Conference}}
* between {{Flagicon|Bahrain}} [[Bahrain]] and {{Flagicon|Abu Dhabi}} [[Emirate of Abu Dhabi|Abu Dhabi]] using the [[Bahraini dinar]]
* between {{Flagicon|Bahrain|variant=1932}} [[Bahrain]], {{Flagicon|Kuwait|variant=1940}} [[Sheikhdom of Kuwait|Kuwait]], {{Flagicon image|Flag of The Imamate of Oman.svg}} [[Oman proper|Oman]], {{Flagicon|Qatar|variant=1949}} [[Qatar]] and the {{Flagicon|Trucial States}} [[Trucial States]], using the [[Gulf rupee]] from 1959 until 1966
* between {{Flagicon image|Flag of Aden (1937–1963).svg}} [[Colony of Aden|Aden]], {{Flag|South Arabia}}, {{Flagicon|Bahrain|variant=1932}} [[Bahrain]], {{Flagicon image|Flag of Kenya (1921–1963).svg}} [[Kenya Colony|Kenya]], {{Flagicon|Kuwait|variant=1940}} [[Sheikhdom of Kuwait|Kuwait]], {{Flagicon image|Flag of The Imamate of Oman.svg}} [[Oman proper|Oman]], {{Flagicon|Qatar|variant=1949}} [[Qatar]], {{Flagicon|British Somaliland}} [[British Somaliland]], {{Flagicon|Trucial States}} the [[Trucial States]], {{Flagicon image|Flag of the Uganda Protectorate.svg}} [[Uganda Protectorate|Uganda]], {{Flagicon image|Flag of Zanzibar Under British Rule.svg}} [[Sultanate of Zanzibar|Zanzibar]] and {{Flagicon|British India}} [[British India]] (later independent {{Flagicon|India}} [[India]]) using the [[Indian rupee]] until 1974
* between {{Flagicon|Belgium}} [[Belgium]] and the {{Flagicon|Luxembourg}} Grand-Duchy of [[Luxemburg]] ([[Belgium-Luxembourg Economic Union]]) using the [[Belgian franc|Belgian/Luxembourgish franc]] from 1921 to the Euro
* between {{Flagicon|British India}} [[British India]] and the {{Flagicon|Straits Settlements}} [[Straits Settlements]] (1837–1867) using the [[Indian rupee]]
* between {{Flagicon|Czech Republic}} [[Czech Republic]] and {{Flagicon|Slovakia}} [[Slovakia]] (briefly from January 1, 1993 to February 8, 1993) using the [[Czechoslovak koruna]]
* between {{Flagicon|Ethiopia}} [[Ethiopia]] and {{Flagicon|Eritrea}} [[Eritrea]] using the [[Ethiopian birr]]
* between {{Flagicon|France}} [[France]], {{Flagicon|Monaco}} [[Monaco]], and {{Flagicon|Andorra}} [[Andorra]] using the [[French franc]]
*between {{Flagicon|Austria-Hungary}} Austria-Hungary and {{Flagicon|Liechtenstein}} [[Liechtenstein]] using the [[Austro-Hungarian krone]]
* between the [[Organization of Eastern Caribbean States|Eastern Caribbean]], {{Flagicon image|Flag of Jamaica (1957–1962).svg}} [[Colony of Jamaica|Jamaica]], {{Flagicon image|Flag of Barbados (1870–1966).svg}} [[History of Barbados|Barbados]], {{Flagicon image|Flag of Trinidad and Tobago (1958–1962).svg}} [[Trinidad and Tobago]] and {{Flagicon|British Guiana}} [[British Guiana]] using the [[British West Indies dollar]]
* between the [[Organization of Eastern Caribbean States|Eastern Caribbean]],  {{Flagicon image|Flag of Barbados (1870–1966).svg}} [[History of Barbados|Barbados]], {{Flagicon image|Flag of Trinidad and Tobago (1958–1962).svg}} [[Trinidad and Tobago]] and {{Flagicon|British Guiana}} [[British Guiana]] using the [[Eastern Caribbean dollar]]
* between {{Flagicon|Italy}} [[Italy]], {{Flagicon|Holy See}} [[Vatican City]], and {{Flagicon|San Marino}} [[San Marino]] using the [[Italian lira]]
* between {{Flagicon|Jamaica}} [[Jamaica]] and the {{Flagicon|Cayman Islands}} [[Cayman Islands]] using the [[Jamaican pound]] and later [[Jamaican dollar]]
* between {{Flagicon image|Flag of Kenya (1921–1963).svg}} [[Kenya Colony|Kenya]], {{Flagicon image|Flag of the Uganda Protectorate.svg}} [[Uganda Protectorate|Uganda]], and {{Flagicon image|Flag of Zanzibar Under British Rule.svg}} [[Sultanate of Zanzibar|Zanzibar]] using the [[East African rupee]]
* between {{Flagicon image|Flag of Kenya (1921–1963).svg}} [[Kenya Colony|Kenya]], {{Flagicon image|Flag of the Uganda Protectorate.svg}} [[Uganda Protectorate|Uganda]], and {{Flagicon image|Flag of Zanzibar Under British Rule.svg}} [[Sultanate of Zanzibar|Zanzibar]]  (and later {{Flag|Tanganyika}}) using the [[East African florin]]
* between {{Flagicon|Kenya}} [[Kenya]], {{Flag|Tanganyika}} and {{Flagicon|Zanzibar}} [[Zanzibar]] (later merged as {{Flagicon|Tanzania}} [[Tanzania]]), {{Flagicon|Uganda}} [[Uganda]], {{Flagicon|South Arabia}} [[South Arabia]], {{Flagicon|British Somaliland}} [[British Somaliland]] and {{Flagicon image|Flag of the Kingdom of Italy.svg}} [[Italian Somaliland]] using the [[East African shilling]]
* [[Latin Monetary Union]] (1865–1927), initially between {{Flagicon|French Third Republic}} [[France]], {{Flagicon|Belgium}} [[Belgium]], {{Flagicon|Kingdom of Italy}} [[Italy]] and {{Flagicon|Switzerland}} [[Switzerland]], and later involving {{Flagicon|Kingdom of Greece}} [[Greece]],<ref name="bolton">{{cite web|url=https://www.theguardian.com/world/2001/dec/10/euro.eu|title=A history of currency unions|last=Bolton|first=Sally|date=10 December 2001|publisher=guardian.co.uk|quote=France persuaded Belgium, Italy, Switzerland and Greece|access-date=26 February 2012}}</ref> {{Flagicon|Kingdom of Romania}} [[Romania]], {{Flag|Spain|1785}} and other countries.
* between {{Flagicon|Liberia}} [[Liberia]] and the {{Flagicon|United States|variant=1912}} [[United States]] using the [[United States dollar]]
* between {{Flagicon|Mauritius}} [[Mauritius]] and {{Flagicon|Seychelles}} [[Seychelles]] using the [[Mauritian rupee]]
* between {{Flagicon image|Flag of Nigeria (1914–1952).svg}} [[Colonial Nigeria|Nigeria]], {{Flagicon image|Flag of The Gambia (1889–1965).svg}} the [[Gambia Colony and Protectorate|Gambia]], {{Flagicon image|Flag of Sierra Leone (1916–1961).svg}} [[Sierra Leone Colony and Protectorate|Sierra Leone]], {{Flagicon|Gold Coast}} [[Gold Coast (British colony)|the Gold Coast]] and {{Flagicon|Liberia}} [[Liberia]] using the [[British West African pound]]
* between {{Flagicon|Kingdom of Prussia|variant=1803}} [[Kingdom of Prussia|Prussia]] and the North German states (1838–1857) using the [[Prussian thaler|North German thaler]]
* between {{Flagicon|Russian Federation|variant=1991}} [[Russia]] and the {{Flagicon image|Flag of the CIS (UEFA Euro 1992).svg}} [[Post-Soviet states|former Soviet republics]] (1991–1993) using the [[Soviet ruble]]
* between {{Flagicon|Qatar}} [[Qatar]] and all the emirates of the {{Flagicon|UAE}} [[United Arab Emirates]], except [[Abu Dhabi]] using the [[Qatari and Dubai riyal]]
* between {{Flagicon|Saudi Arabia|variant=1938}} [[Saudi Arabia]] and {{Flagicon|Qatar|variant=1949}} [[Qatar]] using the [[Saudi riyal]]
* between {{Flagicon image|Flag of the Territory of Papua.svg}} [[Western Samoa Trust Territory|Western Samoa]] and {{Flagicon|New Zealand}} [[New Zealand]] using the [[New Zealand pound]]
* [[Scandinavian Monetary Union]] (1870s until 1924), between {{Flagicon|Denmark}} [[Denmark]], {{Flagicon|Norway}} [[Norway]] and {{Flagicon|Sweden}} [[Sweden]]<ref name="bolton" />
* between the {{Flagicon|Solomon Islands}} [[Solomon Islands]], {{Flagicon|Papua New Guinea}} [[Papua New Guinea]] and {{Flagicon|Australia}} [[Australia]] using the [[Australian dollar]]
*between {{Flagicon|Australia}} [[Australia]], {{Flagicon image|Flag of the Territory of Papua.svg}} [[Territory of Papua|Papua]], {{Flagicon image|Flag of the Territory of New Guinea.svg}} [[Territory of New Guinea|New Guinea]], {{Flagicon image|Civil Ensign of Australia.svg}} [[History of Nauru|Nauru]], {{Flagicon image|Flag of the Solomon Islands (1956–1966).svg}} the [[British Solomon Islands|Solomon Islands]], and {{Flagicon image|Flag of the Gilbert and Ellice Islands (1937–1976).svg}} the [[Gilbert and Ellice Islands]] using the [[Australian pound]]
* between {{Flagicon image|Flag of Bavaria (striped).svg}} [[Bavaria]], {{Flagicon image|Banner of Baden (3^2).svg}} [[Baden]], {{Flagicon image|Flagge Königreich Württemberg.svg}} [[Württemberg]], {{Flagicon image|Flag of the Free City of Frankfurt.svg}} [[Free City of Frankfurt|Frankfurt]], and {{Flagicon image|Flag of Hohenzollern-Hechingen and Sigmaringen.png}} [[House of Hohenzollern|Hohenzollern]] using the [[South German gulden|South German guilder]]
* between {{Flagicon|Spain}} [[Spain]] and {{Flagicon|Andorra}} [[Andorra]] using the [[Spanish peseta]]
* between {{Flagicon|Trinidad and Tobago}} [[Trinidad and Tobago]] and {{Flagicon|Grenada}} [[Grenada]] using the [[Trinidad and Tobago dollar]]
* between {{Flagicon|Brunei}} [[Brunei]], {{Flagicon|Malaysia}} [[Malaysia]], and {{Flagicon|Singapore}} [[Singapore]] (1953–1967) using the [[Malaya and British Borneo dollar]]
* between {{Flagicon image|Flag of Cambodia under French protection.svg}} [[French protectorate of Cambodia|Cambodia]], {{Flagicon image|Flag of French Laos.svg}} [[French protectorate of Laos|Laos]], {{Flagicon image|Flag of France.svg}} [[Guangzhouwan]], {{Flagicon image|First flag of the Nguyen Dynasty.svg}}  [[Annam (French protectorate)|Annam]], {{Flagicon image|Flag of Colonial Annam.svg}} [[Tonkin (French protectorate)|Tonkin]], and {{Flagicon image|Flag of Republic of Cochinchina.svg}} [[French Cochinchina|Cochinchina]] (later {{Flagicon|State of Vietnam}} [[State of Vietnam|Vietnam]]) between 1885 and 1952 using the [[French Indochinese piastre]]
* between {{Flag|South Africa|1928}}, {{Flagicon|South West Africa}} [[South West Africa]], and {{Flagicon image|Flag of the United Kingdom.svg}} [[Bechuanaland Protectorate|Bechuanaland]] (later independent {{Flagicon|Botswana}} [[Botswana]]) using the [[South African rand]]
* between {{Flagicon|Egypt|1922}} [[Egypt]], {{Flagicon image|Flag of Anglo-Egyptian Sudan.svg}} [[Anglo-Egyptian Sudan]], and {{Flagicon image|Ensign of the Palestine Mandate (1927–1948).svg}} [[Mandatory Palestine]] (until 1926) using the [[Egyptian pound]]  
* between {{Flagicon|West Germany}} [[West Germany]] and {{Flagicon|DDR}} [[East Germany]] between 1 July 1990 and 3 October 1990, as part of a temporary, so-called "Monetary, Economic and Social Union" prior to [[German reunification]].
* between what ultimately became the {{Flagicon|Republic of Ireland}} [[Republic of Ireland]] and the {{Flagicon|United Kingdom}} [[United Kingdom]], between 1928 and 1979. The [[Irish Pound]] was held at exactly the same value as Sterling for this period, although it was not accepted for payments in the UK.
* [[Yen Bloc]] (between 1905 and 1945), between the {{Flagicon|Empire of Japan}} [[Empire of Japan]], the {{Flagicon|Korean Empire}} [[Korean Empire]], {{Flagicon|Manchukuo}} [[Manchukuo]], {{Flagicon|Mengjiang}} [[Mengjiang]], the {{Flagicon|Wang Jingwei regime}} [[Wang Jingwei regime]], and Japanese-occupied Southeast Asia prior to and during World War II.

===Never materialized===
* proposed Pan-American monetary union – abandoned in the form proposed by [[Argentina]]
* proposed monetary union between the {{Flagicon|United Kingdom}} [[United Kingdom]] and {{Flagicon|Norway}} [[Norway]] using the [[pound sterling]] during the late 1940s and early 1950s
* proposed gold-backed, pan-African monetary union put forward by [[Muammar Gaddafi]] prior to his death

==See also==
{{Portal|Money|Numismatics}}
* [[List of circulating fixed exchange rate currencies|List of pegged currencies]]
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* [[North American Currency Union]] (Amero)<ref>Not currently on any political agenda, based mostly off conspiracy theories.</ref>

==References==
{{Reflist|40em}}

==Further reading==
* [[Nicola Acocella|Acocella, N.]] and Di Bartolomeo, G. and Tirelli, P. [2007], ‘''Monetary conservatism and fiscal coordination in a monetary union''’, in: ‘''Economics Letters''’, 94(1): 56–63.
* {{cite encyclopedia |last1= Bergin |first1=Paul  |editor= David R. Henderson  |editor-link= David R. Henderson  |encyclopedia=[[Concise Encyclopedia of Economics]] |title=Monetary Union |url=http://www.econlib.org/library/Enc/MonetaryUnion.html |year=2008 |edition= 2nd |publisher=[[Library of Economics and Liberty]] |location=Indianapolis |isbn=978-0865976658 |oclc=237794267}}

==External links==
{{Commons category|Currency unions}}
*[http://news.bbc.co.uk/1/hi/world/africa/721707.stm West Africa opts for currency union]
*[http://www.economist.com/displayStory.cfm?story_id=393224 Economist- Antipodean currencies (Australia and New Zealand)]
*[https://web.archive.org/web/20081218230932/http://www.case.com.pl/upload/publikacja_plik/3460035_058e.pdf Reasons for the collapse of the Rouble Zone]
*[http://www.oecd.org/dataoecd/52/15/23381692.pdf OECD Development Centre – the Rand Zone]

{{Economic integration}}
{{Authority control}}

[[Category:Currency|Union]]
[[Category:Currency unions| ]]
[[Category:International macroeconomics]]
[[Category:Proposed currencies]]
[[Category:Economic integration]]