| Country | Action | Action Date | Effective Date |
|---|
| ALBANIA | Signature | 10/07/1964 | |
| ALGERIA | Signature | 10/07/1964 | |
| ALGERIA | Ratification | 12/06/1968 | |
| ARGENTINA | Signature | 10/07/1964 | |
| ARGENTINA | Ratification | 23/06/1967 | |
| AUSTRIA | Signature | 10/07/1964 | |
| AUSTRIA | Ratification | 23/12/1965 | |
| BELGIUM | Signature | 10/07/1964 | |
| BELGIUM | Approval | 04/11/1965 | |
| BOLIVIA | Signature | 10/07/1964 | |
| BURUNDI | Signature | 10/07/1964 | |
| BURUNDI | Ratification | 09/05/1969 | |
| CAMEROON | Signature | 10/07/1964 | |
| CAMEROON | Ratification | 23/12/1968 | |
| CENTRAL AFRICAN REPUBLIC | Signature | 10/07/1964 | |
| CENTRAL AFRICAN REPUBLIC | Ratification | 26/07/1968 | |
| CHAD | Signature | 10/07/1964 | |
| Channel Islands | Extension | 08/09/1969 | |
| CHILE | Signature | 10/07/1964 | |
| COLOMBIA | Signature | 10/07/1964 | |
| CONGO, REPUBLIC OF | Signature | 10/07/1964 | |
| CONGO, REPUBLIC OF | Approval | 07/09/1966 | |
| CUBA | Signature | 10/07/1964 | |
| DAHOMEY | Signature | 10/07/1964 | |
| DAHOMEY | Approval | 13/01/1967 | |
| DENMARK | Signature | 10/07/1964 | |
| DENMARK | Ratification | 23/12/1965 | |
| ECUADOR | Accession | 30/09/1969 | 11/11/1969 |
| FINLAND | Signature | 10/07/1964 | |
| FINLAND | Ratification | 17/12/1965 | |
| FRANCE | Signature | 10/07/1964 | |
| FRANCE | Approval | 22/01/1966 | |
| French O/seas Postal & Telecom Office Terr. | Signature | 10/07/1964 | |
| French O/seas Postal & Telecom Office Terr. | Approval | 22/01/1966 | |
| GABON | Signature | 10/07/1964 | |
| GABON | Approval | 27/01/1967 | |
| GERMANY FEDERAL REPUBLIC | Signature | 10/07/1964 | |
| GERMANY FEDERAL REPUBLIC | Ratification | 27/06/1966 | |
| GREECE | Signature | 10/07/1964 | |
| GREECE | Ratification | 08/05/1968 | |
| GUINEA | Signature | 10/07/1964 | |
| GUINEA | Ratification | 05/09/1966 | |
| INDONESIA | Signature | 10/07/1964 | |
| Isle of Man | Extension | 08/09/1969 | |
| ITALY | Signature | 10/07/1964 | |
| ITALY | Ratification | 12/07/1968 | |
| IVORY COAST | Signature | 10/07/1964 | |
| IVORY COAST | Approval | 28/10/1965 | |
| JAPAN | Signature | 10/07/1964 | |
| JAPAN | Approval | 22/07/1965 | |
| LAOS | Signature | 10/07/1964 | |
| LAOS | Approval | 25/09/1967 | |
| LEBANON | Signature | 10/07/1964 | |
| LIECHTENSTEIN | Signature | 10/07/1964 | |
| LIECHTENSTEIN | Ratification | 05/10/1967 | |
| LUXEMBOURG | Signature | 10/07/1964 | |
| LUXEMBOURG | Ratification | 29/12/1965 | |
| MALAGASY REPUBLIC | Signature | 10/07/1964 | |
| MALAGASY REPUBLIC | Approval | 25/08/1965 | |
| MALI | Signature | 10/07/1964 | |
| MALI | Ratification | 18/12/1965 | |
| MAURITANIA | Accession | 22/03/1967 | |
| MONACO | Signature | 10/07/1964 | |
| MONACO | Ratification | 30/09/1968 | |
| MOROCCO | Signature | 10/07/1964 | |
| MOROCCO | Approval | 07/04/1967 | |
| NETHERLANDS THE | Signature | 10/07/1964 | |
| NETHERLANDS THE | Ratification | 08/08/1969 | |
| NICARAGUA | Signature | 10/07/1964 | |
| NIGER | Signature | 10/07/1964 | |
| NIGER | Approval | 04/02/1966 | |
| NORWAY | Signature | 10/07/1964 | |
| NORWAY | Approval | 01/12/1965 | |
| PARAGUAY | Signature | 10/07/1964 | |
| ROMANIA | Signature | 10/07/1964 | |
| SAN MARINO | Signature | 10/07/1964 | |
| SAN MARINO | Approval | 11/10/1967 | |
| SENEGAL | Signature | 10/07/1964 | |
| SENEGAL | Ratification | 26/09/1967 | |
| SOMALI DEMOCRATIC REPUBLIC | Signature | 10/07/1964 | |
| SPAIN | Signature | 10/07/1964 | |
| SPAIN | Ratification | 09/11/1966 | |
| Spain, Territories In Africa | Signature | 10/07/1964 | |
| Spain, Territories In Africa | Ratification | 09/11/1966 | |
| SWEDEN | Signature | 10/07/1964 | |
| SWEDEN | Ratification | 13/12/1966 | |
| SWITZERLAND | Signature | 10/07/1964 | |
| SWITZERLAND | Ratification | 04/02/1966 | |
| TOGO | Signature | 10/07/1964 | |
| TOGO | Approval | 28/08/1967 | |
| TUNISIA | Signature | 10/07/1964 | |
| TUNISIA | Ratification | 13/09/1966 | |
| TURKEY | Signature | 10/07/1964 | |
| TURKEY | Ratification | 08/09/1970 | |
| UNITED ARAB REPUBLIC | Signature | 10/07/1964 | |
| UNITED ARAB REPUBLIC | Ratification | 30/06/1967 | |
| UNITED KINGDOM | Accession | 08/09/1969 | 30/09/1969 |
| UNITED KINGDOM | Declaration | 08/09/1969 | |
| UPPER VOLTA | Signature | 10/07/1964 | |
| UPPER VOLTA | Approval | 04/02/1967 | |
| URUGUAY | Signature | 10/07/1964 | |
| VATICAN CITY | Signature | 10/07/1964 | |
| VATICAN CITY | Ratification | 22/04/1968 | |
| VENEZUELA | Signature | 10/07/1964 | |
| VENEZUELA | Ratification | 12/09/1969 | |
| YEMEN | Signature | 10/07/1964 | |
| YUGOSLAVIA | Signature | 10/07/1964 | |
| ZAIRE | Signature | 10/07/1964 | |