| Country | Action | Action Date | Effective Date |
|---|
| ABYSSINIA | Signature | 16/07/1926 | |
| ABYSSINIA | Ratification | 16/07/1926 | |
| ALBANIA | Signature | 18/06/1921 | |
| ALBANIA | Ratification | 13/07/1921 | |
| ARGENTINE REPUBLIC | Signature | 28/12/1935 | |
| Australia | Signature | 18/06/1921 | |
| Australia | Ratification | 04/08/1921 | |
| AUSTRIA | Signature | 18/06/1921 | |
| AUSTRIA | Ratification | 23/07/1921 | |
| BELGIUM | Signature | 09/05/1921 | |
| BELGIUM | Ratification | 29/08/1921 | |
| BOLIVIA | Signature | 20/06/1921 | |
| BOLIVIA | Ratification | 07/07/1936 | |
| BRAZIL | Signature | 16/12/1920 | |
| BRAZIL | Ratification | 29/10/1921 | |
| BRITISH EMPIRE | Signature | 16/12/1920 | |
| BRITISH EMPIRE | Ratification | 04/08/1921 | |
| BULGARIA | Signature | 11/04/1921 | |
| BULGARIA | Ratification | 12/08/1921 | |
| Canada | Signature | 30/03/1921 | |
| Canada | Ratification | 04/08/1921 | |
| CHILE | Signature | 07/09/1921 | |
| CHILE | Ratification | 20/07/1928 | |
| CHINA | Signature | 16/12/1920 | |
| CHINA | Ratification | 13/05/1922 | |
| COLOMBIA | Signature | 16/12/1920 | |
| COLOMBIA | Ratification | 06/01/1932 | |
| COSTA RICA | Signature | 16/12/1920 | |
| CUBA | Signature | 16/12/1920 | |
| CUBA | Ratification | 12/01/1922 | |
| CZECHOSLOVAKIA | Signature | 19/05/1921 | |
| CZECHOSLOVAKIA | Ratification | 02/09/1921 | |
| DENMARK | Signature | 16/12/1920 | |
| DENMARK | Ratification | 13/06/1921 | |
| DOMINICAN REPUBLIC | Signature | 30/09/1924 | |
| DOMINICAN REPUBLIC | Ratification | 04/02/1933 | |
| EGYPT | Signature | 30/05/1939 | |
| ESTONIA | Signature | 18/10/1921 | |
| ESTONIA | Ratification | 02/05/1923 | |
| FINLAND | Signature | 28/06/1921 | |
| FINLAND | Ratification | 06/04/1922 | |
| FRANCE | Signature | 16/12/1920 | |
| FRANCE | Ratification | 07/08/1921 | |
| GERMANY | Signature | 10/12/1926 | |
| GERMANY | Ratification | 11/03/1927 | |
| GREECE | Signature | 16/12/1920 | |
| GREECE | Ratification | 03/10/1921 | |
| GUATEMALA | Signature | 17/12/1926 | |
| HAITI | Ratification | 07/09/1921 | |
| HAITI | Signature | 04/10/1921 | |
| HUNGARY | Signature | 01/08/1923 | |
| HUNGARY | Ratification | 20/11/1925 | |
| India | Signature | 16/12/1920 | |
| India | Ratification | 04/08/1921 | |
| IRAQ | Signature | 22/09/1938 | |
| Irish Free State | Letter | 21/08/1926 | |
| ITALY | Signature | 18/12/1920 | |
| ITALY | Ratification | 20/06/1921 | |
| JAPAN | Signature | 19/12/1920 | |
| JAPAN | Ratification | 16/11/1921 | |
| LATVIA | Signature | 21/01/1922 | |
| LIBERIA | Signature | 24/07/1921 | |
| LIECHTENSTEIN | Signature | 29/03/1939 | |
| LITHUANIA | Signature | 05/10/1921 | |
| LITHUANIA | Ratification | 16/05/1922 | |
| LUXEMBOURG | Signature | 31/01/1921 | |
| LUXEMBOURG | Ratification | 15/09/1930 | |
| MONACO | Signature | 22/04/1937 | |
| NETHERLANDS THE | Signature | 16/12/1920 | |
| NETHERLANDS THE | Ratification | 06/08/1921 | |
| New Zealand | Signature | 16/12/1920 | |
| New Zealand | Ratification | 04/08/1921 | |
| NICARAGUA | Signature | 14/09/1929 | |
| NORWAY | Signature | 16/12/1920 | |
| NORWAY | Ratification | 20/08/1921 | |
| PANAMA | Signature | 16/12/1920 | |
| PANAMA | Ratification | 14/06/1929 | |
| PARAGUAY | Signature | 16/12/1920 | |
| PARAGUAY | Ratification | 11/05/1933 | |
| PERSIA | Signature | 04/11/1921 | |
| PERSIA | Ratification | 25/04/1931 | |
| PERU | Signature | 14/09/1929 | |
| PERU | Ratification | 29/03/1932 | |
| POLAND | Signature | 16/12/1920 | |
| POLAND | Ratification | 26/08/1921 | |
| PORTUGAL | Signature | 16/12/1920 | |
| PORTUGAL | Ratification | 08/10/1921 | |
| ROMANIA | Signature | 15/04/1921 | |
| ROMANIA | Ratification | 08/08/1921 | |
| SALVADOR | Signature | 16/12/1920 | |
| SALVADOR | Ratification | 29/08/1930 | |
| SERB-CROAT-SLOVENE STATE | Signature | 30/05/1921 | |
| SERB-CROAT-SLOVENE STATE | Ratification | 12/08/1921 | |
| SIAM | Signature | 16/12/1920 | |
| SIAM | Ratification | 27/02/1922 | |
| South Africa | Signature | 16/12/1920 | |
| South Africa | Ratification | 08/04/1921 | |
| SPAIN | Signature | 06/04/1921 | |
| SPAIN | Ratification | 30/08/1921 | |
| SWEDEN | Signature | 16/12/1920 | |
| SWEDEN | Ratification | 21/02/1921 | |
| SWITZERLAND | Signature | 16/12/1920 | |
| SWITZERLAND | Ratification | 25/07/1921 | |
| TURKEY | Signature | 12/03/1936 | |
| UNITED KINGDOM | | | |
| UNITED STATES OF AMERICA | Signature | 09/12/1929 | |
| URUGUAY | Signature | 16/12/1920 | |
| URUGUAY | Ratification | 27/09/1921 | |
| VENEZUELA | Signature | 16/12/1920 | |
| VENEZUELA | Ratification | 02/12/1921 | |