As of June 2016, the World Customs Organization has a total of 180 members. The European Communities (now: European Union) joined "on an interim basis akin to those enjoyed by WCO Members".
The 175 sovereign states, 4 customs territories and one customs union are divided into the following regional groups:
East and Southern Africasovereign statesAngola— 1990-09-26Botswana— 1978-08-25Burundi— 1964-10-20Comoros— 1993-07-01Djibouti—2008-03-19Eritrea— 1995-08-08Ethiopia— 1973-08-06Kenya— 1965-05-24Lesotho— 1978-08-02Madagascar— 1964-02-18Malawi— 1966-06-06Mauritius— 1973-03-29Mozambique— 1987-07-01Namibia— 1992-07-01Rwanda— 1964-03-03Seychelles— 2000-07-25Somalia— 2012-10-04South Sudan— 2012-07-18South Africa— 1964-03-24Swaziland— 1981-05-15Tanzania— 1964-11-07Uganda— 1964-11-03Zambia— 1978-09-27Zimbabwe— 1981-03-19Europesovereign states (founders in bold)Albania— 1992-08-31Andorra— 1998-09-03Armenia— 1992-06-30Austria— 1953-01-21Azerbaijan— 1992-06-17Belarus— 1993-12-16Belgium— 1952-12-11Bosnia and Herzegovina— 2008-07-04Bulgaria— 1973-08-01Croatia— 1993-07-01Cyprus— 1967-08-31Czech Republic— 1993-01-01Denmark— 1951-10-19Estonia— 1992-06-18Finland— 1961-01-27France— 1952-10-06Georgia— 1993-10-26Germany— 1952-11-04Greece— 1951-12-10Hungary— 1968-09-16Iceland— 1971-02-15Ireland— 1952-09-23Israel— 1958-05-23Italy— 1952-11-20Kazakhstan— 1992-06-30Kyrgyzstan— 2000-02-10Latvia— 1992-06-22Lithuania— 1992-06-18Luxembourg— 1953-01-23Macedonia— 1994-07-01Malta— 1968-07-06Moldova— 1994-10-28Montenegro— 2006-10-24Netherlands— 1953-01-23Norway— 1951-08-06Poland— 1974-07-17Portugal— 1953-01-26Romania— 1969-01-15Russian Federation— 1991-07-08Serbia— 2001-03-27Slovakia— 1993-01-01Slovenia— 1992-09-07Spain— 1952-07-13Sweden— 1952-10-17Switzerland— 1952-12-19Tajikistan— 1997-07-01Turkey— 1951-06-06Turkmenistan— 1993-05-17Ukraine— 1992-06-26United Kingdom— 1952-09-12Uzbekistan— 1992-07-28partially recognised stateKosovo— 2017-03-03customs unionEuropean UnionFar East, South and South East Asia, Australasia and the Pacific Islandssovereign statesAfghanistan— 2004-08-10Australia— 1961-01-05Bangladesh— 1978-07-01Bhutan— 2002-02-12Brunei Darussalam— 1996-07-01Cambodia— 2001-04-03PR China— 1983-07-18Fiji— 1997-07-01India— 1971-02-15Indonesia— 1957-04-30Iran— 1959-10-16Japan— 1964-01-15Korea (Republic of)— 1968-07-02Laos— 2007-01-16Malaysia— 1964-06-30Maldives— 1995-09-08Mongolia— 1991-09-17Myanmar— 1991-03-25Nepal— 1986-07-22New Zealand— 1963-05-16Pakistan— 1955-11-16Papua New Guinea— 2002-03-18Philippines— 1980-10-01Samoa— 2001-10-01Singapore— 1975-07-09Sri Lanka— 1967-05-29Thailand— 1972-02-04Timor-Leste— 2003-09-19Tonga— 2005-07-01Vanuatu— 2009-11-17Vietnam— 1993-07-01customs territoriesHong Kong— 1987-07-01Macau— 1993-07-07North of Africa, Near and Middle Eastsovereign statesAlgeria— 1966-12-19Bahrain— 2001-04-18Egypt— 1956-10-26Iraq— 1990-06-06Jordan— 1964-01-01Kuwait— 1993-10-04Lebanon— 1960-05-20Libya— 1983-01-11Morocco— 1968-07-01Oman— 2000-09-11Qatar— 1992-05-04Saudi Arabia— 1973-05-08Sudan— 1960-06-08Syria— 1959-11-19Tunisia— 1966-07-20United Arab Emirates— 1979-02-07Yemen— 1993-07-01partially recognised statePalestine— 2015-03-24South America, North America, Central America and the Caribbeansovereign statesArgentina— 1968-07-01Bahamas— 1974-08-16Barbados— 1999-01-07Belize— 2008-04-22Bolivia— 1997-08-14Brazil— 1981-01-19Canada— 1971-10-12Chile— 1966-07-01Colombia— 1993-07-11Costa Rica— 2001-08-29Cuba— 1988-07-01Dominican Republic— 2004-07-28Ecuador— 1997-12-16El Salvador— 2005-07-07Guatemala— 1985-02-22Guyana— 1976-07-29Haiti— 1958-01-31Honduras— 2005-12-08Jamaica— 1963-03-29Mexico— 1988-02-08Nicaragua— 1998-09-24Panama— 1996-03-08Paraguay— 1969-10-03Peru— 1970-01-27Saint Lucia— 2005-05-12Trinidad and Tobago— 1973-10-15United States— 1970-11-05Uruguay— 1977-09-16Venezuela— 1996-07-01customs territoriesNetherlands Antilles— 1988-07-11Bermuda— 1990-07-01West and Central Africasovereign statesBenin— 1998-11-09Burkina Faso— 1966-09-16Cameroon— 1965-04-09Cape Verde— 1992-07-01Central African Republic— 1986-07-28Chad— 2005-02-16Congo, Republic of the— 1975-09-02Côte d'Ivoire— 1963-09-02Democratic Republic of the Congo— 1972-07-26Gabon— 1965-02-18Gambia— 1987-10-14Ghana— 1968-08-01Guinea— 1991-10-30Guinea-Bissau— 2010-08-19Liberia— 1975-01-07Mali— 1987-08-07Mauritania— 1979-10-02Niger— 1981-07-01Nigeria— 1963-08-21São Tomé and Príncipe— 2009-09-23Senegal— 1976-03-10Sierra Leone— 1975-11-06Togo— 1990-02-12The following United Nations member states are not members of the WCO: Antigua and Barbuda, Saint Kitts and Nevis, Saint Vincent and the Grenadines, Grenada, Dominica, Suriname, Equatorial Guinea, Liechtenstein, Monaco, San Marino, North Korea, Palau, Solomon Islands, Micronesia, Kiribati, Marshall Islands, Tuvalu, and Nauru. Non-member states also include Vatican City, Cook Islands, Niue, Taiwan, and the other states with limited recognition.