| Country | Action | Action Date | Effective Date |
|---|
| ALBANIA | Signature | 20/04/1921 | |
| ALBANIA | Ratification | 18/10/1921 | |
| ANTIGUA AND BARBUDA | Succession | 25/10/1988 | 01/11/1981 |
| Antilles | Extension | 01/01/1986 | |
| Aruba | Extension | 01/01/1986 | |
| AUSTRALIA | Accession | 31/10/1922 | |
| AUSTRIA | Signature | 20/04/1921 | |
| AUSTRIA | Ratification | 10/07/1924 | |
| BELGIUM | Signature | 20/04/1921 | |
| BELGIUM | Ratification | 16/05/1927 | |
| BOLIVIA | Signature | 20/04/1921 | |
| BRITISH EMPIRE | Signature | 20/04/1921 | |
| BRITISH EMPIRE | Declaration | 20/04/1921 | |
| BRITISH EMPIRE | Ratification | 09/10/1922 | |
| BULGARIA | Signature | 20/04/1921 | |
| BULGARIA | Ratification | 11/07/1922 | |
| CANADA | Accession | 31/10/1922 | |
| CHILE | Signature | 20/04/1921 | |
| CHILE | Ratification | 19/03/1928 | |
| CHINA | Signature | 20/04/1921 | |
| CROATIA | Succession | 03/08/1992 | 08/10/1991 |
| Curacao | Extension | 20/04/1921 | |
| CZECH REPUBLIC | Succession | 09/02/1996 | 01/01/1993 |
| CZECHOSLOVAKIA | Signature | 20/04/1921 | |
| CZECHOSLOVAKIA | Ratification | 08/09/1924 | |
| DANZIG | Accession | 10/01/1933 | |
| DENMARK | Signature | 20/04/1921 | |
| DENMARK | Ratification | 13/11/1922 | |
| East Indies | Extension | 20/04/1921 | |
| ESTONIA | Signature | 20/04/1921 | |
| ESTONIA | Statement | 30/08/1929 | |
| FIJI | Succession | 15/03/1972 | |
| FINLAND | Accession | 22/09/1922 | |
| FRANCE | Signature | 20/04/1921 | |
| FRANCE | Statement | 20/04/1921 | |
| GERMAN DEMOCRATIC REPUBLIC | Re-Application | 31/01/1974 | 04/06/1958 |
| GERMAN DEMOCRATIC REPUBLIC | Communication | 17/06/1976 | |
| GERMANY | Accession | 10/11/1931 | |
| GERMANY FEDERAL REPUBLIC | Re-Application | 01/01/1953 | |
| GERMANY FEDERAL REPUBLIC | Re-Application | 20/07/1955 | |
| GERMANY FEDERAL REPUBLIC | Declaration | 24/02/1976 | |
| GREECE | Signature | 20/04/1921 | |
| GREECE | Ratification | 03/01/1928 | |
| GUATEMALA | Signature | 20/04/1921 | |
| Hong Kong | Extension | 09/10/1922 | |
| Hong Kong | Withdrawal | 01/07/1997 | 01/07/1997 |
| HONG KONG SAR | Application | 06/06/1997 | 01/07/1997 |
| HUNGARY | Accession | 18/05/1928 | |
| INDIA | Signature | 20/04/1921 | |
| INDIA | Ratification | 09/10/1922 | |
| IRAQ | Accession | 17/04/1935 | |
| ITALY | Signature | 20/04/1921 | |
| ITALY | Statement | 20/04/1921 | |
| JAPAN | Signature | 20/04/1921 | |
| JAPAN | Ratification | 20/02/1924 | |
| LATVIA | Signature | 20/04/1921 | |
| LATVIA | Ratification | 12/02/1924 | |
| LESOTHO | Succession | 23/10/1973 | |
| LITHUANIA | Signature | 20/04/1921 | |
| MALAWI | Succession | 06/07/1964 | |
| MALTA | Succession | 21/09/1964 | |
| MAURITIUS | Succession | 12/03/1968 | |
| MEXICO | Accession | 17/10/1935 | |
| MONGOLIA | Accession | 15/10/1976 | |
| NETHERLANDS THE | Signature | 20/04/1921 | |
| NETHERLANDS THE | Statement | 20/04/1921 | |
| Netherlands West Indies | Extension | 20/04/1921 | |
| NEW ZEALAND | Signature | 20/04/1921 | |
| NEW ZEALAND | Ratification | 09/10/1922 | |
| NORWAY | Signature | 20/04/1921 | |
| NORWAY | Ratification | 04/09/1923 | |
| PANAMA | Signature | 20/04/1921 | |
| PERSIA | Signature | 20/04/1921 | |
| POLAND | Signature | 20/04/1921 | |
| POLAND | Ratification | 20/12/1924 | |
| PORTUGAL | Signature | 20/04/1921 | |
| ROUMANIA | Accession | 22/02/1923 | |
| RWANDA | Accession | 10/02/1965 | |
| SERB-CROAT-SLOVENE STATE | Signature | 20/04/1921 | |
| SIAM | Accession | 29/11/1922 | |
| SLOVAK REPUBLIC | Succession | 28/05/1993 | 01/01/1993 |
| SOLOMON ISLANDS | Accession | 03/09/1981 | |
| SOUTH AFRICA | Accession | 31/10/1922 | |
| SOVIET UNION | Accession | 16/05/1935 | |
| SPAIN | Signature | 20/04/1921 | |
| SPAIN | Ratification | 01/07/1929 | |
| ST VINCENT AND THE GRENADINES | Succession | 05/09/2001 | 27/10/1979 |
| Surinam | Extension | 20/04/1921 | |
| SWAZILAND | Succession | 16/10/1970 | |
| SWEDEN | Signature | 20/04/1921 | |
| SWEDEN | Ratification | 19/01/1925 | |
| SWITZERLAND | Statement | 01/01/1905 | |
| SWITZERLAND | Signature | 20/04/1921 | |
| TURKEY | Accession | 27/06/1933 | |
| UNITED KINGDOM | Signature | 20/04/1921 | |
| UNITED KINGDOM | Ratification | 09/10/1922 | |
| URUGUAY | Signature | 20/04/1921 | |
| West Indies | | | |
| YUGOSLAVIA | Ratification | 07/05/1930 | |
| ZIMBABWE | Succession | 01/12/1998 | 18/04/1998 |