Here are some key happenings of past years.

1. A political system may change, such as Russia becoming the USSR, but the original dates of membership remain.
2. Once a member of the UPU, the nation will always remain a member, even if they don’t pay their dues.
3. No nation has ever stated “I Quit the UPU.”
4. South Africa was expelled due to apartheid by a 1979 UPU Congress, but was immediately readmitted since the nation is a member of the United Nations Organization, and any member of the UNO is automatically a member of the UPU.
5. At one time, Taiwan was considered China for the UNO and the UPU, before continental China existed for the UPU. When continental China became a member of the UNO, Taiwan “disappeared” and this country is now considered a “China province” on UPU records.
6. The Republic of Cyprus, Turkey, was declared illegal by a UPU Congress in 1979 and all member nations were advised to refuse to handle any mail “bearing these illegal postage stamps.”

Abu Dhabi -- 1966, Dec. 31: joined the UPU
Afghanistan -- 1928, April 1: joined the UPU
Afrique Occidental: Portuguese province -- joined the UPU Jan. 1, 1922; left the UPU Nov. 11, 1975.
Afrique Orientale: Portuguese province -- joined the UPU Jan.1, 1922; left the UPU Oct., 11, 1978.
Aland Islands -- 1918, Feb. 12: joined the UPU as part of Finland
Alaska -- 1875, July 1: joined the UPU with the USA.
Albania -- 1922, March 1: joined the UPU
Algeria -- 1907, Oct. 1: changed UPU affiliation with French Colonies and Protectorates; 1964, May 28: changed UPU affiliation as independent of France
Andorra -- UN member country whose status with the UPU has not yet been settled
Angola -- 1977, March 3: joined the UPU
Anguilla -- 1875, Jan. 1: joined the UPU as an Overseas Territory of Great Britain; 1988, Jan. 11: joined the UPU
Antigua & Barbuda -- 1994, Jan. 20: joined the UPU
Argentina -- 1878, April 1: joined the UPU; 1929, June 28: renewed membership in UPU
Armenia -- 1992, Sept.14: joined the UPU
Aruba -- 1875, July 1: joined the UPU with the Netherlands; 1877, May 1: joined the UPU as part of the Netherlands Antilles
Ascension -- 1875, Jan. 1: joined the UPU as an Overseas Territory of Great Britain
Australia -- 1907, Oct. 1: joined the UPU, includes Norfolk Island, Papua, New Guinea and Nauru; 1969, Apr. 17: Nauru changed UPU affiliation to being independent; 1976, June 4: Papua and New Guinea changed UPU affiliation to Papua New Guinea
Austria -- 1875, July 1: joined the UPU as charter member, Austria-Hungary; 1900, Jan. 25: joined UPU as Austria; 1900, Apr. 25: changed UPU affiliation, named Austria and Hungary; 1918, Dec. 20: changed UPU affiliation to being independent; 1946, Nov. 11: changed UPU affiliation to Austria
Azerbaijan -- 1993, April 1: joined the UPU
Bahamas -- 1974, April 24: joined the UPU
Bahrain -- 1973, Dec. 21: joined the UPU
Bangladesh -- 1947, Nov. 10: joined the UPU with Pakistan; 1973, Feb. 7: changed UPU affiliation to an independent nation
Barbados -- 1967, Nov. 11: joined the UPU
Bassas da India -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
Belarus -- 1947, May 13: changed UPU affiliation as independent from Russia; 1996: changed UPU affiliation to own name
Belgian Congo -- 1908: renamed the Belgian Congo, admitted to the UPU; 1923, Aug. 31: Ruanda-Urundi became independent, affiliated with the UPU
Belgium -- 1875, July 1: joined the UPU as charter member
Belize -- 1982, Oct. 1:joined the UPU
Benin -- 1961, April 27: joined the UPU
Bermuda -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain,
Bhutan -- 1969, March 7: joined the UPU
Bohemia and Moravia -- 1939, Sep. 1: joined the UPU with Germany; 1939, Oct. 7: changed UPU affiliation to be German Protectorate of Bohemia and Moravia
Bolivia -- 1886, April 1: joined the UPU
Bosnia and Herzegovina -- 1892, July 1: Bosnia Herzegovina joined the UPU; 1921, Dec. 24: changed UPU affiliation to Kingdom of Serbs, Croats and Slovenes; 1993, Jan. 26: rejoined the UPU
Botswana -- 1968, Jan. 12: joined the UPU
Brazil -- 1877, July 1: joined the UPU
British Australian Colonies -- 1891, Oct.1: became affiliated with the UPU; 1907, Oct.1: changed UPU affiliation to British Colonies and Possessions.
British Virgin Islands -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain
British Colonies -- 1877, Apr. 1: joined the UPU; 1879, Jan. 1: changed UPU affiliation to include British Colonies and Possessions; 1891, Oct. 1: changed UPU affiliation to all British colonies; 1907, Oct. 1; changed UPU affiliation to include additional Colonies and Possessions; 1940, July 1: changed UPU affiliation to include overseas territories, Protectorates and Mandated areas; 1953: changed UPU affiliation to include British colonies, overseas territories, Protectorates, Mandated areas and Northern Ireland
British Colonies and Possessions, Oriental Africa -- 1895, Dec.1: joined the UPU; 1901, Apr.1: changed UPU affiliation to Oriental Africa and Uganda; 1907, Oct. 1: joined the UPU; British Colonies and Possessions in South Africa, Australia, Canada. British India and New Zealand, plus other Colonies, and Possessions; 1921: changed UPU affiliation to Great Britain, Diverse Dominum, Colonies and Protectorates.
British Indian Ocean Territory (BIOT) -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain
British Solomon Islands -- 1907, Sept. 3: joined the UPU
Brunei -- 1985, Jan.15: joined the UPU as Brunei Darussalam
Bulgaria -- 1879, July 1: joined the UPU
Burkino Faso -- 1963, March 29: joined the UPU
Burma -- 1876, July 1: joined the UPU as British Burma, part of India; 1949, Oct. 4: joined the UPU; 1989: changed UPU affiliation to Myanmar
Burundi -- 1963, April 6: joined the UPU
Cambodia -- 1951, Dec. 21: joined the UPU
Cameroons -- 1960, July 26: joined the UPU
Canada -- 1878, July 1: joined the UPU with New Territories; 1907, Oct. 1: changed UPU affiliation to include British Colonies and Possessions
Cape Verde -- 1976, Sept. 30: joined the UPU
Cayman Islands -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain,
Central African Republic -- 1961, June 28: joined the UPU
Ceylon -- 1947, July 5: joined the UPU; 1949, July 13: rejoined the UPU as independent within Commonwealth; 1956, May 10: rejoined the UPU
Chad -- 1961, June 23: joined the UPU
Channel Islands -- 1971: changed UPU affiliation from Great Britain, became independent.
Chile -- 1881, April 1: joined the UPU
China -- 1914, March 1: joined the UPU, includes Hong Kong, Macao, Mongolia, Sinkiang, Tibet
1963, Aug. 24: changed affiliation with the UPU, Mongolia became independent.
Clipperton Island -- 1876, Jan.1: joined the UPU with France.
Colombia -- 1881, July 1: joined the UPU as the United States of Panama; 1904, June 11: changed affiliation with UPU to independent nation; 1904, Aug.: changed affiliation with UPU to USA
Comoro Islands -- 1976, July 29: joined the UPU
Congo, Democratic Republic of -- 1886, Jan. 1: joined the UPU with Kingdom of Ruanda-Urundi; 1908: changed UPU affiliation to Belgium Congo; 1961, July 5: changed UPU affiliation to Democratic Republic of Congo
Congo, Republic of -- 1886, Jan. 1: joined the UPU; 1960, July 1: joined the UPU as part of French Community
Cook Islands -- 1907, Oct.1: joined the UPU with New Zealand.
Costa Rica -- 1883, Jan. 1: joined the UPU
Crete -- 1902, July 1: joined the UPU; 1920, combined with Greece within the UPU.
Croatia -- 1921, Dec. 24: joined the UPU; 1929, Oct. 3: changed affiliation with the UPU combined with Yugoslavia; 1942, Apr. 7: changed affiliation with the UPU independent from Yugoslavia; 1945: became part of the Yugoslav Federation, provisional overprints on Croatian stamps used, changed UPU affiliation to part of Yugoslavia; 1992, July 20: rejoined the UPU.
Crozet Archipelago -- 1876, Jan.1: joined the UPU with France as Crozet Islands.
Cuba -- 1877, May 1: became member of UPU; 1877, June 15: changed UPU affiliation to Spanish Colony; 1902, Oct. 4: rejoined the UPU
Curaçao -- 1922, Jan.1: affiliated with the UPU as Curaçao and Surinam with Netherlands Colonies; 1948: changed UPU affiliation; renamed Netherlands Antilles and Surinam
Cyprus -- 1961, Nov. 23: joined the UPU as a republic within the British Commonwealth; 1975, Feb. 13: Turkish Cypriot federated state declared, Turkish Cyprus stamp not recognized by the UPU
Czechoslovakia -- 1920, May 18: joined the UPU; 1939, June 15: changed UPU affiliation to Protectorate of Bohemia and Moravia; 1945, Aug. 10: changed UPU affiliation to Czechoslovakia; 1992, Dec. 31: changed UPU affiliation to Czech and Slovak Republic; 1993, March 18: rejoined the UPU as Czech Republic.
Dahomey -- 1961, Apr. 27: joined the UPU
Danish Antilles -- 1887: joined the UPU; 1916, Aug. 4 -Mar. 31, 1917: changed UPU affiliation to Islands with the USA
Danish Colonies - 1877, Sep. 1: affiliated with the UPU, Danish Antilles added later in 1877
Danish West Indies -- 1877, Sept. 1: joined the UPU
Danzig -- 1921, Oct. 1: joined the UPU; 1939, Nov. 24: changed UPU affiliation to Free City of Danzig with Germany
Denmark -- 1875, July 1: joined the UPU as charter member; includes Faroe Islands, Greenland.
Djibouti -- 1978, June 6: joined the UPU
Dominica -- 1980, Jan. 31: joined the UPU as Dominican Commonwealth.
Dominican Republic -- 1880, Oct. 1: joined the UPU; 1980, Jan. 31: changed UPU affiliation to Dominican Republic
Dubai -- 1963, June 14: joined the UPU, British postal agency withdrawn; 1973, Mar. 30: changed UPU affiliation to United Arab Emirates.
East Timor -- UN member country whose status with the UPU has not yet been settled
Ecuador -- 1880, July 1: joined the UPU as Republic of Ecuador
Egypt -- 1875, July 1: joined the UPU as charter member, included Sudan; 1960-1965: changed UPU affiliation to United Arab Republic
Equatorial Guinea, Republic of -- 1969: joined UPU; 1970, July 24: changed UPU affiliation to Equatorial Guinea
Eritrea -- 1936: affiliated with the UPU through Ethiopia; 1952: changed UPU affiliation to federated state with Ethiopia; 1962, Nov. 14: changed UPU affiliation to be part of Ethiopia; 1993, Aug. 19: joined the UPU as Eritrea
Estonia -- 1922, July 7: joined the UPU; 1940, Aug. 6: changed UPU affiliation to part of the USSR; 1992, April 30: changed UPU affiliation as Republic of Estonia.
Ethiopia -- 1908, Nov. 1: Empire of Ethiopia joined the UPU; 1936: changed UPU affiliation to Ethiopia; 1941, May 5: change UPU affiliation back to Empire of Ethiopia; 1945, Jan. 1: changed UPU affiliation to Ethiopia.
Ethiopia, French Offices - 1908: offices closed when Ethiopia joined the UPU.
Europa - 1876, Jan. 1: joined the UPU as a French Overseas Department.
Falkland Islands -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain,
Faroe Islands -- 1875, July 1: joined the UPU, included with Denmark
Fiji -- 1971, June 18: joined the UPU
Finland -- 1918, Feb. 12: joined the UPU
France -- 1876, Jan. 1: joined the UPU as France, Algeria, and Monaco; French Overseas Departments included: French Guinea, Guadeloupe, Martinque, Reunion, Mayotte, St. Barthelemy, St. Martin, St. Pierre and Miquelon, Territories included: Bassas da India, Clipperton Island, Crozet Islands, Europa, French Polynesia, French Southern and Antarctic Territories, Glorieuses, Juan de Nova, Kerguelen Islands, New Caledonia, St. Paul and Amsterdam Islands, Terre Adelie, Tromelin, Wallis and Futuna Islands; 1884: changed UPU affiliation to France, Algeria and Tunisia; 1888: changed UPU affiliation to France and Algeria; 1907, Oct.1: joined the UPU; 1925: posts of France to operate Principality of Monaco posts, change of UPU affiliation; 1946: changed UPU affiliation to include French overseas territories; 1947: changed UPU affiliation to include French overseas and Monaco; 1952: changed UPU affiliation to include French administered territories; 1955: changed UPU affiliation to include Andorra; 1957: changed UPU affiliation to add territories represented by the French Post Office and Telecommunications.
France and Algeria -- 1888: joined the UPU; 1907, Oct. 1: changed UPU affiliation to France.
French Colonies -- 1876, July 1: member of the UPU with French Protectorates; 1907, Oct.1: changed UPU affiliation to French Colonies and Protectorates; 1925: changed UPU affiliation to France; 1946: changed UPU affiliation to Territories of the French Republic.
French Guinea -- 1876, Jan.1: joined the UPU with France.
French Polynesia -- 1876, Jan.1: joined the UPU with France.
French Southern and Antarctic Territories -- 1876, Jan.1: joined the UPU with France.
Glorious Islands -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
Gabon -- 1961, July 17: joined the UPU
Gambia -- 1974, Oct. 9: joined the UPU.
Georgia -- 1993, April 1: joined the UPU
German Democratic Republic -- 1990, Oct. 3: changed UPU affiliation, reunited with (West) Germany
German Protectorates -- 1887, June 1: joined the UPU; 1902, Feb. 24: changed UPU affiliation to include Africa, Asia and Australia.
Germany -- 1875, July 1: joined the UPU as charter member; 1939, Sep.1: changed UPU affiliation to include Protectorate of Bohemia and Moravia; 1955, Mar. 21: changed UPU affiliation to include Saar; 1973, June 1: changed UPU affiliation for separate Democratic Republic of Germany.
Ghana -- 1957, Oct. 10: joined the UPU
Gibraltor -- 1875, July 1: joined the UPU with Great Britain.
Glorious Islands -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
Great Britain -- 1875, July 1: joined the UPU as charter member, includes Overseas Territories Anguilla, Ascension, Bermuda, British Indian Ocean Territory, British Virgin Islands, Cayman Islands, Falkland Islands, Gibraltor, Montserrat, Pitcairn, Henderson Ducie and Oeno (Islands), Northern Ireland, South Georgia and South Sandwich Islands, Tristan da Cunha, Turks and Caicos Islands; 1971: changed UPU affiliation; Channel Islands, Jersey and Guernsey became independent.
Greece -- 1875, July 1; joined the UPU as charter member
Greenland -- 1875, July 1: joined the UPU, included with Denmark
Grenada -- 1978, Jan. 30: joined the UPU
Guadeloupe -- 1876, Jan. 1: joined the UPU as a French Overseas Department,
Guam -- 1875, July 1: joined the UPU with the USA
Guatemala -- 1881, Aug. 1: joined the UPU
Guernsey -- 1971: changed UPU affiliation, became independent.
Guinea -- 1959, May 6: joined the UPU as Republic of Guinea
Guinea-Bissau – 1974, May 30, joined the UPU
Haiti -- 1881, July 1: joined the UPU
Hawaii -- 1882, Jan. 1: became affiliated with the UPU as Kingdom of Hawaii; 1898, Aug.12: annexed by the US, changed affiliation with UPU to a Possession of the USA; 1881, July 1: joined the UPU; 1907, Oct.1: changed UPU affiliation to include Hawaii.
Hejaz-Nejd -- 1957: changed UPU affiliation with Spanish Colonies-Africa-Sahara, and Ifni leaving, see Saudi Arabia
Heligoland -- 1879, July 1: joined the UPU
Henderson Ducie and Oeno (Islands) -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain.
Honduras -- 1879, April 1: joined the UPU
Hong Kong -- 1914, Mar. 1: joined the UPU included with China, People’s Republic
Hungary -- 1875, July 1: joined the UPU, Austrian-Hungarian Empire; 1900, Jan. 25: joined UPU as Hungary Iceland; 1875: joined UPU as a Danish possession; 1919, Nov. 15: joined the UPU.
India -- 1876, July 1: joined the UPU as British India; including Aden, Hindustan and British Burma; 1907, Oct.: British India changed UPU affiliation to British Colonies and Possessions
India Route -- Via Brindisi; UPU permitted a surcharge on mail traveling this route in 1881-2.
Indo-China -- 1896, Oct. 1: joined the UPU with Cambodian and part of Indo-China, Laos and part of Indo-China, and Viet Nam; 1951, Oct. 20: UPU affiliation of Viet Nam changed to Republic of Viet Nam; 1951, Dec. 21: UPU affiliation of Cambodia changed to Khmere Republic; 1952, May 2: UPU affiliation changed to independent Laos, Cambodia and Viet Nam.
Indo-China, French -- 1897: admitted as an equal member of the UPU.
Indonesia -- 1877, May 1: joined the UPU; 1948, Sep. 20: rejoined the UPU as Indonesian Republic; 1949, July 13: rejoined UPU as Indonesia.
Iran -- 1877, Sept. 1: joined the UPU; 1935, Jan. 29: affiliated with the UPU as Iran.
Iraq -- 1929, April 22; joined the UPU with Kuwait
Ireland -- 1923, Sept.6: joined the UPU as Free State of Ireland; 1937, Dec. 29: renewed UPU affiliation as Ireland.
Ireland, Northern -- 1875, July 1: joined the UPU as a Great Britain Overseas Territory.
Isle of Man -- 1971: changed UPU affiliation to be independent of Great Britain.
Israel -- 1949, Dec. 24: joined the UPU.
Isthmus of Panama -- UPU permitted a surcharge on mail traveling this route in 1881-2.
Italian Colonies -- 1904, July 1: joined the UPU; 1907, Oct. 1: changed UPU affiliation to include all Italian colonies; 1940, July 1: changed UPU affiliation to include Oriental Africa and all colonies and possessions in Africa.
Italian East Africa -- 1940: July 1: Italian East Africa became a UPU member; 1943 - June 3, 1952: changed UPU affiliation to British Administration; 1950, Apr. 1: changed UPU affiliation to Italian Administration; 1952, June 4: changed UPU affiliation to Libyan Jamahiriya, (Libya Socialist).
Italy -- 1875, July 1: joined the UPU as charter member.
Ivory Coast -- 1961, May 23: joined the UPU. Jamaica; 1963, Aug. 29: joined the UPU.
Japan -- 1877, June 1: joined the UPU; 1922, Jan.1: changed UPU affiliation to include Japanese Dependencies; Marianias, Marshall and Carolines, Japanese Dependencies: Mariannes, Marshall and Caroline Islands; 1922, Jan. 1: joined the UPU; 1947, Apr. 2: became part of the USA.
Jersey -- 1971: changed UPU affiliation, became independent from Great Britain.
Jordan -- 1947, May 16: joined the UPU as Royal Kingdom of Transjordan; 1951, June 7: changed UPU affiliation to Royal Kingdom of Jordan.
Juan de Nova -- 1876, Jan. 1: joined the UPU as a French Overseas Territory.
Kazakhstan -- 1992, Aug. 27: joined the UPU.
Kenya -- 1964, Oct. 27: joined the UPU.
Kerguelen Archipelago -- 1876, Jan. 1: joined the UPU as a French Overseas Territory.
Kiribati -- 1984, Aug. 14: joined the UPU.
Korea -- 1900, Jan. 1: joined the UPU.
Korea, Democratic People’s Republic (North Korea) -- 1900, Jan. 1: joined the UPU as Republic of Korea; 1906: joined the UPU as the Empire of Korea; 1922, Jan. 1: changed UPU affiliation to Chosen; 1949, Dec. 17: became independent, changed UPU affiliation to Republic of Korea.
Korea, Republic (South Korea) -- 1900, Jan. 1: joined the UPU as republic of Korea; 1974, June 6: changed UPU affiliation to the Popular Democratic Republic of Korea.
Kuwait -- 1941, Oct. 31: changed UPU affiliation from Iraq to British India; 1947, Nov. 10: joined the UPU with Pakistan; 1960, Feb. 16: changed UPU affiliation.
Kyrgyzstan -- several bogus issues, reported to the UPU in many letters; 1993, Jan. 26: joined the UPU.
Labuan -- 1889: joined the UPU.
Laos - 1952, May 20: joined the UPU
Latvia - 1921, Oct.1: joined the UPU; 1940, Aug. 5: changed UPU affiliation to the USSR; 1992, June 17: rejoined the UPU as Republic of Latvia
Lebanon -- 1923, Oct. 23: joined the UPU as Federated State of Syria; 1931, May 12: changed UPU affiliation; 1946, May 15: rejoined the UPU as Republic of Lebanon.
Lesotho -- 1967, Sept. 6: joined the UPU.
Liberia - 1967, Sept. 6: joined the UPU.
Libya -- 1946, May 15: joined the UPU; 1952, June 4: rejoined the UPU; 1977: changed UPU affiliation to as Jamahiriya Libya. (Socialist Libya).
Liechtenstein -- 1875, July 1: joined the UPU as charter member affiliated with Austria-Hungary; 1921, Feb.13: post office administered by Switzerland, changed UPU affiliation to be with Switzerland; 1962, April 13: joined the UPU as independent nation.
Lithuania -- 1922, Jan. 1: joined the UPU; 1940, Aug. 3: joined the USSR, left the UPU; 1992, Jan. 10: rejoined the UPU as Republic of Lithuania.
Luxembourg -- 1875, July 1: joined the UPU as charter member.
Macao -- 1914, Mar.1: joined the UPU included with China, People’s Republic; 1978, Dec. 28: changed UPU affiliation to independent Macao.
Macedonia -- 1993, July 12: joined the UPU.
Madagascar -- 1961, Nov. 2: joined the UPU as Republic of Madagascar.
Malawi -- 1966, Oct. 25: joined the UPU.
Malaysia -- 1958, Jan. 17: joined the UPU as Federation of Malaysia; 1963, Sept.16: changed UPU affiliation to Malaysia.
Maldive Islands -- 1967, Aug. 15: joined the UPU.
Mali, Republic of -- 1961, April 21: joined the UPU.
Marshall Islands -- UN member country whose status with the UPU has not yet been settled
Malta -- 1965, May 21: joined the UPU
Mariana Islands -- 1922, Jan. 1: changed UPU affiliation to include Japan Dependencies.
Marshall and Carolines -- 1922, Jan. 1: changed UPU affiliation to include Japanese Dependencies
Martinique -- 1876, Jan. 1: joined the UPU with French Overseas Departments.
Mauritania -- 1967, Mar.22: joined the UPU.
Mauritius -- 1969, Aug. 29: joined the UPU.
Mayotte -- 1876, Jan. 1: joined the UPU as a French Overseas Department
Mexico -- 1879, April 1: joined the UPU
Micronesia -- UN member country whose status with the UPU has not yet been settled.
Moldovia -- 1992, Nov. 16: joined UPU.
Monaco -- 1876, Jan.1: joined the UPU with France; 1955, Oct. 12: changed the UPU affiliation.
Mongolia -- 1914, Mar.1: joined the UPU with China; 1963, Aug. 24: changed the UPU affiliation.
Montenegro, Kingdom of -- 1875, June 30: membership in the UPU as charter member; 1921, Dec. 24: changed UPU affiliation, became Kingdom of Serbs, Croats and Slovenes,
Montserrat -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain.
Morocco -- 1920, Oct.1: joined UPU; 1956, Oct. 15: changed the UPU affiliation to independent Morocco
Mozambique -- 1978, Oct. 11: joined the UPU.
Namibia -- 1966, Oct. 27: joined the UPU under responsibility of the United Nations.
Nauru -- 1969, April 17: joined the UPU.
Nepal -- 1956, Oct. 11: joined the UPU
Netherlands -- 1875, July 1: joined the UPU as a charter member, includes Aruba, Netherlands Antilles.
Netherlands Antilles -- 1875, July 1: joined the UPU with The Netherlands; 1877: joined the UPU; 1948, Sep.3: changed UPU affiliation to include Surinam, Ned(erlandse) Antillen appeared on all stamps
Netherlands Colonies -- 1877, May 1: became affiliated with the UPU; 1922, Jan. 1: added Curaçao, Surinam and Netherlands Indies to UPU affiliation.
Netherlands Indies -- 1922, Jan. 1: joined the UPU affiliated with Netherlands Colonies; 1948, Sep. 20: changed UPU affiliation to Indonesia.
New Caledonia -- 1876, Jan. 1: joined the UPU as a French Overseas Territory.
New Guinea, British -- 1892: joined UPU.
New South Wales -- 1891: became member of the UPU
New Zealand -- 1907, Oct. 1: joined the UPU; includes Cook Islands, Niue, Tokelau.
Nicaragua -- 1882, May 1: joined the UPU
Niger -- 1961, June 12: joined the UPU.
Nigeria -- 1961, July 10: joined the UPU,
Niue -- 1907, Oct.1: Joined the UPU with New Zealand.
Norfolk Island -- 1907, Oct.: joined the UPU as part of Australia.
North Borneo -- 1891: joined the UPU
Norway -- 1875, July 1: joined the UPU as a charter member.
Oil Rivers Protectorate -- 1879, Jan. 1: British West Africa colonies joined the UPU.
Oman -- 1875, Aug. 17: joined the UPU; 1947, Nov. 10: joined the UPU with Pakistan; 1966, Apr. 30: Oman Sultanate took over postal administration of Muscat and Oman, issued first stamps under its own postal authority, changed UPU affiliation to autonomous; 1971, Aug.17: rejoined the UPU as Sultanate of Oman.
Orange Free State -- 1898, Jan.: became member of UPU; 1899, Jan.1: changed affiliation with UPU to British Protectorate of South Africa.
Pakistan -- 1947, Nov. 10: joined the UPU.
Palau -- UN member country whose status with the UPU has not yet been settled
Panama -- 1904, June 11: Canal Zone had its own stamps, joined the UPU; 1904, Aug.1: changed UPU affiliation to Panama Canal Zone; 1940, July 1: changed UPU affiliation to all USA Possessions, with Panama Canal Zone.
Papua New Guinea. -- 1976, June 4: joined the UPU as Papua New Guinea.
Paraguay.-- 1881, July 1: joined the UPU.
Persia -- 1877, Sep. 1: affiliated with the UPU; 1935, Jan. 29: changed UPU affiliation to Iran.
Peru -- 1879, April 1: joined the UPU.
Phillippines -- 1877: Spanish colonies joined the UPU and foreign stamps stopped being used,; 1922, Jan. 1: joined the UPU.
Pitcairn Islands -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain,
Poland -- 1919, May 1: joined the UPU; 1939, Sept.1: German occupation “Deutsche Post Osten” overprint on stamps of Germany, changed affiliation with the UPU “with Germany”; 1945, July 20: changed affiliation with the UPU, became independent; 1956: changed UPU affiliation to Popular Republic of Poland.
Portugal -- 1875, July 1: joined the UPU as a charter member.
Portuguese Africa -- 1907, Oct.1: Portuguese African Colonies joined the UPU; 1922, Jan.1: changed UPU affiliation to Portuguese Provinces, Occidental Africa,
Portuguese Colonies -- 1877, July 1: became members of the UPU; 1907: changed UPU affiliation to include Portuguese African Colonies; 1922, Jan. 1: changed UPU affiliation with additional Portuguese Colonies.
Puerto Rico -- 1875, July 1: joined the UPU with the USA
Qatar -- 1969, Jan. 31: joined the UPU
Queensland -- 1891: joined the UPU
Reunion -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
Romania -- 1875, July 1: joined the UPU as a charter member; 1923, Aug. 31: joined the UPU under the Mandate of Belgium; 1963, Apr. 6: changed UPU affiliation, became independent as Rwanda and Burundi.
Russia -- 1875, July 1: joined the UPU as a charter member; 1924, June 24: changed UPU affiliation, became USSR, first postage due stamp
Rwanda -- 1963, April 6: joined the UPU.
Saar -- 1959, July 6: Saar stamps discontinued, German Federal Republic stamps and currency used detached from the UPU.
Sabah -- 1963, Sep. 16: joined the UPU through Malaysia.
St. Barthelemy -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
St. Christopher-Nevis-Anguilla -- 1988, Jan. 11: joined the UPU
St. Lucia -- 1980, July 10: joined the UPU.
St. Martin -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
St. Paul and Amsterdam Islands -- 1876, Jan. 1: joined the UPU as a French Overseas Territory.
St. Pierre and Miquelon -- 1876, Jan. 1: joined the UPU as a French Overseas Department.
Straits Settlements -- 1877, April 1: joined the UPU.
St. Thomas and Prince Islands -- 1977, Aug. 22: joined the UPU
St. Vincent -- 1881: joined the UPU.
St. Vincent Grenadines -- 1981, Feb. 3: joined the UPU.
Salvador, El -- 1879, April 1: joined the UPU.
Samoa -- 1891: joined the UPU, however mail to the USA required an additional 5-cent American stamp to pay for inland delivery; 1940, July 1: changed UPU affiliation to all USA Possessions including Samoa.
San Marino -- 1989, Aug. 9: joined the UPU; 1915, July 1: changed UPU affiliation to independent
Sarawak -- 1963, Sept.16: joined the UPU, Federation of Malaysia, uses their stamps with overprint “Sarawak”; 1966, Jan. 8: changed UPU affiliation to Singapore.
Sarre -- 1920, Sep.1: admitted to the UPU.
Saudi Arabia – 1957, changed UPU affiliate as Saudi Arabia. See Hejaz-Nejd.
Senegal -- 1961, June 14: joined the UPU
Serbia -- 1874: Serbia was an original member of the General Postal Union; 1875, July 1: joined the UPU; 1921, Dec. 24: rejoined the UPU as Kingdom of Serbs, Croates and Slovenes; 1929, Oct. 3: rejoined the UPU as Yugoslavia; 2001, June 18: rejoined the UPU as Federal Republic of Yugoslavia; 2003, Feb. 4: rejoined the UPU as Serbia & Montenegro.
Seychelles -- 1977, Oct. 7: joined the UPU.
Siam -- 1885, July 1: joined the UPU; 1939, June 24: changed UPU affiliation to Thailand
Sierra Leone -- 1962, Jan. 29: joined the UPU
Singapore -- 1966, Jan. 8: joined the UPU.
Sinkiang -- 1914, Mar.1: joined the UPU with China
Slovakia -- 1920, May 18: joined the UPU; 1939, June 17: joined the UPU as German Protectorate; 1940: first personal delivery stamp, changed UPU affiliation to leave German Protectorate; 1945, Aug. 10: changed affiliation with UPU as a constituent republic of Czechoslovakia; 1993, March 18: rejoined the UPU as Slovakia Republic.
Slovenia -- 1921, Dec. 24: joined the UPU; 1992, Aug. 27: rejoined the UPU.
Solomon Islands -- 1907: joined the UPU as the British Solomon Islands; 1984, May 4: rejoined the UPU as Solomon Islands.
Somalia -- 1950, Apr. 1: joined the UPU under Italian Trusteeship; 1959, April 1: joined the UPU under Italian Administration; 1960, July 1: former Italian colony merged with British Somaliland Protectorate to form independent Republic of Somalia, changed UPU affiliation to sovereign state.
Somali Democratic Republic -- 1950, April 1: Italians, with ten year United Nations Mandate, ran Italian Somaliland, changed UPU affiliation to Somalia.
South Africa -- 1893, Jan. 1: joined the UPU; 1899, Jan. 1: changed UPU affiliation to South Africa Colonies and Protectorates; 1910, June 1: changed UPU affiliation to Union of South Africa; 1961, May 31: withdrew from British Commonwealth, became Republic of South Africa, changed affiliation with the UPU; 1981, June 19: changed UPU affiliation to South Africa; 1994, Aug. 22: changed UPU affiliation to Republic of South Africa.
South Australia -- 1891: joined the UPU.
South Georgia and the South Sandwich (Islands) -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain.
South West Africa -- 1922, Mar. 1: joined the UPU; 1954: changed UPU affiliation as administered by Union of South Africa.
Spain -- 1875, July 1: joined the UPU as charter member.
Spanish Colonies -- 1877, May 1: became affiliated with UPU; 1899, Dec. 7: added Golf of Guinea to UPU membership.
Spanish Guinea -- 1899, Dec.7: joined the UPU; 1928: changed UPU affiliation to Spanish Guinea, Spanish Occidental Africa and Spanish Sahara.
Sri Lanka -- 1949, July 13: joined the UPU.
Sudan -- 1875, July 1: became charter member of the UPU through affiliation with Egypt; 1956, July 27: changed affiliation with UPU to Independent Republic of Sudan.
Surinam -- 1877, May 1: joined the UPU; 1922, Jan. 1: added to the UPU affiliation with Netherlands Colonies; 1976, April 20: changed UPU affiliation as Republic of Surinam.
Swaziland -- 1969, Nov. 7: joined the UPU.
Sweden -- 1875, July 1: joined the UPU as a charter member.
Switzerland -- 1875, July 1: joined the UPU as a charter member.
Syria -- 1923, Oct. 30: French Federated States admitted to the UPU; 1931, May 12: changed UPU affiliation as French Territory of Syria with Lebanon; 1946, May 15: changed UPU affiliation to an independent republic.
Tajikistan -- 1994, June 9: joined the UPU
Tanganyika -- 1963, Mar. 29: joined the UPU; 1964, Apr. 26: merged with Zanzibar, changed UPU affiliation to United Republic of Tanganyika and Zanzibar
Tanzania -- 1963, March 29: Tanzania, Kenya and Uganda joined the UPU; 1964, April 26: merged with People’s Republic of Zanzibar to become United Republic of Tanzania and Zanzibar, changed UPU affiliation
Tasmania -- 1891: joined the UPU
Terre Adelie -- 1876, Jan. 1: joined the UPU as a French Overseas Territory
Thailand -- 1885, July 1: Siam joined the UPU; 1939, June 24: affiliated with UPU as Thailand
Tibet -- 1914, Mar.1: joined the UPU with China
Togo -- 1886: joined the UPU with other German colonies; 1962, Mar. 21: joined the UPU.
Tokelau -- 1907, Oct. 1: joined the UPU with New Zealand.
Tonga -- 1893, Feb. 13: first official stamp, adopted the UPU rates; 1972, Jan. 26: joined the UPU, includes Niuafo’ou,
Transvaal -- 1893: joined the UPU.
Trinidad and Tobago -- 1963, June 15: joined the UPU.
Tristan da Cunha -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain; 1952, Jan.1: joined the UPU as a British colony.
Tromelin -- 1876, Jan. 1: joined the UPU as a French Overseas Territory.
Tunisia -- 1888, July 1: French protectorate, changed UPU affiliation to Kingdom of Tunisia; 1956, Mar. 20: UPU affiliation to Tunisia as a sovereign state; 1956, Nov. 1: changed UPU affiliation to participating state,
Turkey -- 1875, July 1: joined the UPU as a charter member.
Turkish Republic of Northern Cyprus -- stamps illegal based on UPU regulations
Turkmenistan -- 1993, Jan. 26: joined the UPU,
Turks and Caicos Islands -- 1875, July 1: joined the UPU as an Overseas Territory of Great Britain
Tuvalu -- 1981, Feb. 3: joined the UPU
Uganda -- 1901, April: joined the UPU as British Protectorate; 1964, Feb. 13: changed UPU affiliation.
Ukraine -- 1947, May 13: changed UPU affiliation as independent from Russia.
United Arab Emirates -- 1973, March 30: joined the UPU.
United States of America -- 1875, July 1: joined the UPU as charter member; includes Alaska, Guam, Puerto Rico, Virgin Islands of the USA, Trust Territory of the Pacific Islands; 1900, Feb. 25: USA possessions became affiliated with UPU; 1907, Oct. 1: changed UPU affiliation to include Hawaii, Panama Canal Zone; 1940, July 1: changed UPU affiliation to include Samoa, Panama Canal Zone; 1947, Apr. 2: changed UPU affiliation to include territories supervised by the USA; 1953, July 1: changed UPU affiliation to Territories of the USA,
Upper Volta -- 1963, Mar. 29: joined the UPU
Uruguay -- 1880, July 1: joined the UPU
Uzbekistan -- 1994, Feb. 24: joined the UPU.
Vanuatu -- 1982, July 16: joined the UPU
Vatican City -- 1929, June 1: created by Lateran Treaty with Italy, joined UPU.
Venezuela -- 1880, Jan. 1: joined the UPU
Victoria -- 1891: joined the UPU
Viet Nam -- 1951, Oct. 20: joined the UPU as Republic of Viet Nam
Viet Nam, South -- 1976, Mar. 15: changed UPU affiliation to Republic of South Viet Nam; 1976, Aug. 23: changed UPU affiliation to Socialist Republic of Viet Nam.
Virgin Islands -- 1875, July 1: joined the UPU with the USA.
Wallis and Futuna -- 1876, Jan. 1: joined the UPU as a French Overseas Territory.
Western Australia -- 1891: joined the UPU.
Yemen, Kingdom of -- 1930, Jan. 1: first foreign and domestic issue; joined the UPU; 1990, May 22: changed affiliation with UPU to Yemen Arab Republic (North Yemen) and the People’s Democratic Republic of Yemen (South Yemen) planned to merge to form the Republic of Yemen, government ministries merged but civil war delayed completion.
Yemen, People’s Democratic Republic of -- 1968, June 28: joined the UPU; 1990, May 22: changed UPU affiliation to Republic of Yemen.
Yugoslavia -- 1875, July 1: joined the UPU; 1921, Dec. 24: continued membership in the UPU; 1929, Oct. 3: name changed to Kingdom of Yugoslavia, changed affiliation with UPU, included Croatia; 2001, June 18: continued membership in the UPU as Serbia and Montenegro; 2003, Feb. 4: changed UPU affiliation to The State Union of Serbia and Montenegro
Zambia -- 1967, March 22: joined the UPU.
Zimbabwe -- 1981, July 31: joined the UPU.
Zululand -- 1888: joined the UPU.