| Country | Classification | Entered into Force |
|---|---|---|
| Albania | E-2 | January 4, 1998 |
| Argentina | E-1 | December 20, 1854 |
| Argentina | E-2 | December 20, 1854 |
| Armenia | E-2 | March 29, 1996 |
| Australia | E-1 | December 16, 1991 |
| Australia | E-2 | December 27, 1991 |
| Australia 12 | E-3 | September 2, 2005 |
| Austria | E-1 | May 27, 1931 |
| Austria | E-2 | May 27, 1931 |
| Azerbaijan | E-2 | August 2, 2001 |
| Bahrain | E-2 | May 30, 2001 |
| Bangladesh | E-2 | July 25, 1989 |
| Belgium | E-1 | October 3, 1963 |
| Belgium | E-2 | October 3, 1963 |
| Bolivia | E-1 | November 09, 1862 |
| Bolivia 13 | E-2 | June 6, 2001 |
| Bosnia and Herzegovina 11 | E-1 | November 15, 1982 |
| Bosnia and Herzegovina 11 | E-2 | November 15, 1982 |
| Brunei | E-1 | July 11, 1853 |
| Bulgaria | E-2 | June 2, 1954 |
| Cameroon | E-2 | April 6, 1989 |
| Canada | E-1 | January 1, 1994 |
| Canada | E-2 | January 1, 1994 |
| Chile | E-1 | January 1, 2004 |
| Chile | E-2 | January 1, 2004 |
| China (Taiwan) 1 | E-1 | November 30, 1948 |
| China (Taiwan) 1 | E-2 | November 30, 1948 |
| Colombia | E-1 | June 10, 1948 |
| Colombia | E-2 | June 10, 1948 |
| Congo (Brazzaville) | E-2 | August 13, 1994 |
| Congo (Kinshasa) | E-2 | July 28, 1989 |
| Costa Rica | E-1 | May 26, 1852 |
| Costa Rica | E-2 | May 26, 1852 |
| Croatia 11 | E-1 | November 15, 1982 |
| Croatia 11 | E-2 | November 15, 1982 |
| Czech Republic 2 | E-2 | January 1, 1993 |
| Denmark 3 | E-1 | July 30, 1961 |
| Denmark | E-2 | December 10, 2008 |
| Ecuador 14 | E-2 | May 11, 1997 |
| Egypt | E-2 | June 27, 1992 |
| Estonia | E-1 | May 22, 1926 |
| Estonia | E-2 | February 16, 1997 |
| Ethiopia | E-1 | October 8, 1953 |
| Ethiopia | E-2 | October 8, 1953 |
| Finland | E-1 | August 10, 1934 |
| Finland | E-2 | December 1, 1992 |
| France 4 | E-1 | December 21, 1960 |
| France 4 | E-2 | December 21, 1960 |
| Georgia | E-2 | August 17, 1997 |
| Germany | E-1 | July 14, 1956 |
| Germany | E-2 | July 14, 1956 |
| Greece | E-1 | October 13, 1954 |
| Grenada | E-2 | March 3, 1989 |
| Honduras | E-1 | July 19, 1928 |
| Honduras | E-2 | July 19, 1928 |
| Ireland | E-1 | September 14, 1950 |
| Ireland | E-2 | November 18, 1992 |
| Israel 15 | E-1 | April 3, 1954 |
| Israel 15 | E-2 | May 1, 2019 |
| Italy | E-1 | July 26, 1949 |
| Italy | E-2 | July 26, 1949 |
| Jamaica | E-2 | March 7, 1997 |
| Japan 5 | E-1 | October 30, 1953 |
| Japan 5 | E-2 | October 30, 1953 |
| Jordan | E-1 | December 17, 2001 |
| Jordan | E-2 | December 17, 2001 |
| Kazakhstan | E-2 | January 12, 1994 |
| Korea (South) | E-1 | November 7, 1957 |
| Korea (South) | E-2 | November 7, 1957 |
| Kosovo 11 | E-1 | November 15, 1882 |
| Kosovo 11 | E-2 | November 15, 1882 |
| Kyrgyzstan | E-2 | January 12, 1994 |
| Latvia | E-1 | July 25, 1928 |
| Latvia | E-2 | December 26, 1996 |
| Liberia | E-1 | November 21, 1939 |
| Liberia | E-2 | November 21, 1939 |
| Lithuania | E-2 | November 22, 2001 |
| Luxembourg | E-1 | March 28, 1963 |
| Luxembourg | E-2 | March 28, 1963 |
| Macedonia 11 | E-1 | November 15, 1982 |
| Macedonia 11 | E-2 | November 15, 1982 |
| Mexico | E-1 | January 1, 1994 |
| Mexico | E-2 | January 1, 1994 |
| Moldova | E-2 | November 25, 1994 |
| Mongolia | E-2 | January 1, 1997 |
| Montenegro 11 | E-1 | November 15, 1882 |
| Montenegro 11 | E-2 | November 15, 1882 |
| Morocco | E-2 | May 29, 1991 |
| Netherlands 6 | E-1 | December 5, 1957 |
| Netherlands 6 | E-2 | December 5, 1957 |
| New Zealand 16 | E1 | June 10, 2019 |
| New Zealand 16 | E2 | June 10, 2019 |
| Norway 7 | E-1 | January 18, 1928 |
| Norway 7 | E-2 | January 18, 1928 |
| Oman | E-1 | June 11, 1960 |
| Oman | E-2 | June 11, 1960 |
| Pakistan | E-1 | February 12, 1961 |
| Pakistan | E-2 | February 12, 1961 |
| Panama | E-2 | May 30, 1991 |
| Paraguay | E-1 | March 07, 1860 |
| Paraguay | E-2 | March 07, 1860 |
| Philippines | E-1 | September 6, 1955 |
| Philippines | E-2 | September 6, 1955 |
| Poland | E-1 | August 6, 1994 |
| Poland | E-2 | August 6, 1994 |
| Portugal 17 | E-1 | March 15, 2024 |
| Portugal 17 | E-2 | March 15, 2024 |
| Romania | E-2 | January 15, 1994 |
| Senegal | E-2 | October 25, 1990 |
| Serbia 11 | E-1 | November 15,1882 |
| Serbia 11 | E-2 | November 15,1882 |
| Singapore | E-1 | January 1, 2004 |
| Singapore | E-2 | January 1, 2004 |
| Slovak Republic 2 | E-2 | January 1, 1993 |
| Slovenia 11 | E-1 | November 15, 1982 |
| Slovenia 11 | E-2 | November 15, 1982 |
| Spain 8 | E-1 | April 14, 1903 |
| Spain 8 | E-2 | April 14, 1903 |
| Sri Lanka | E-2 | May 1, 1993 |
| Suriname 9 | E-1 | February 10, 1963 |
| Suriname 9 | E-2 | February 10, 1963 |
| Sweden | E-1 | February 20, 1992 |
| Sweden | E-2 | February 20, 1992 |
| Switzerland | E-1 | November 08, 1855 |
| Switzerland | E-2 | November 08, 1855 |
| Thailand | E-1 | June 8, 1968 |
| Thailand | E-2 | June 8, 1968 |
| Togo | E-1 | February 5, 1967 |
| Togo | E-2 | February 5, 1967 |
| Trinidad & Tobago | E-2 | December 26, 1996 |
| Tunisia | E-2 | February 7, 1993 |
| Turkey | E-1 | February 15, 1933 |
| Turkey | E-2 | May 18, 1990 |
| Ukraine | E-2 | November 16, 1996 |
| United Kingdom 10 | E-1 | July 03, 1815 |
| United Kingdom 10 | E-2 | July 03, 1815 |
| Yugoslavia 11 | E-1 | November 15, 1882 |
| Yugoslavia 11 | E-2 | November 15, 1882 |