| Country | Action | Action Date | Effective Date |
|---|
| ALBANIA | Accession | 16/12/1920 | |
| ALBANIA | Withdrawal | 13/04/1939 | |
| ARGENTINA | Accession | 10/01/1920 | |
| ARGENTINA | Re-Accession | 26/09/1933 | |
| Australia | Signature | 28/06/1919 | |
| Australia | Ratification | 10/01/1920 | |
| AUSTRIA | Accession | 16/12/1920 | |
| BELGIUM | Signature | 28/06/1919 | |
| BELGIUM | Ratification | 10/01/1920 | |
| BOLIVIA | Signature | 28/06/1919 | |
| BOLIVIA | Ratification | 10/01/1920 | |
| BRAZIL | Signature | 28/06/1919 | |
| BRAZIL | Ratification | 10/01/1920 | |
| BRAZIL | Withdrawal | 12/06/1926 | |
| BULGARIA | Accession | 16/12/1920 | |
| Canada | Signature | 28/06/1919 | |
| Canada | Ratification | 10/01/1920 | |
| CHILE | Accession | 10/01/1920 | |
| CHILE | Withdrawal | 14/05/1938 | |
| CHINA | Signature | 28/06/1919 | |
| CHINA | Ratification | 10/01/1920 | |
| COLOMBIA | Accession | 16/02/1920 | |
| COSTA RICA | Accession | 16/12/1920 | |
| COSTA RICA | Withdrawal | 01/01/1925 | |
| CUBA | Signature | 28/06/1919 | |
| CUBA | Ratification | 08/03/1920 | |
| CZECHOSLOVAKIA | Signature | 28/06/1919 | |
| CZECHOSLOVAKIA | Ratification | 10/01/1920 | |
| DENMARK | Accession | 08/03/1920 | |
| ECUADOR | Signature | 28/06/1919 | |
| FINLAND | Accession | 16/12/1920 | |
| FRANCE | Signature | 28/06/1919 | |
| FRANCE | Ratification | 10/01/1920 | |
| GERMANY | Signature | 28/06/1919 | |
| GERMANY | Ratification | 10/01/1920 | |
| GERMANY | Withdrawal | 21/10/1933 | |
| GREECE | Signature | 28/06/1919 | |
| GREECE | Ratification | 30/03/1920 | |
| GUATEMALA | Signature | 28/06/1919 | |
| GUATEMALA | Ratification | 10/01/1920 | |
| GUATEMALA | Withdrawal | 13/05/1936 | |
| HAYTI | Signature | 28/06/1919 | |
| HAYTI | Ratification | 30/06/1920 | |
| HAYTI | Withdrawal | 16/02/1942 | |
| HEJAZ | Signature | 28/06/1919 | |
| HONDURAS | Signature | 28/06/1919 | |
| HONDURAS | Ratification | 03/11/1920 | |
| HONDURAS | Withdrawal | 22/06/1936 | |
| HUNGARY | Withdrawal | 11/04/1939 | |
| India | Signature | 28/06/1919 | |
| India | Ratification | 10/01/1920 | |
| ITALY | Signature | 28/06/1919 | |
| ITALY | Ratification | 10/01/1920 | |
| ITALY | Withdrawal | 11/12/1937 | |
| JAPAN | Signature | 28/06/1919 | |
| JAPAN | Ratification | 10/01/1920 | |
| JAPAN | Withdrawal | 27/03/1933 | |
| LIBERIA | Signature | 28/06/1919 | |
| LIBERIA | Ratification | 30/06/1920 | |
| LUXEMBOURG | Accession | 16/12/1920 | |
| MEXICO | Withdrawal | 14/12/1932 | |
| NETHERLANDS THE | Accession | 09/03/1920 | |
| New Zealand | Signature | 28/06/1919 | |
| New Zealand | Ratification | 10/01/1920 | |
| NICARAGUA | Signature | 28/06/1919 | |
| NICARAGUA | Ratification | 03/11/1920 | |
| NICARAGUA | Withdrawal | 26/06/1936 | |
| NORWAY | Accession | 05/03/1920 | |
| PANAMA | Signature | 28/06/1919 | |
| PANAMA | Ratification | 25/11/1920 | |
| PARAGUAY | Accession | 10/01/1920 | |
| PARAGUAY | Withdrawal | 23/02/1935 | |
| PERSIA | Accession | 10/01/1920 | |
| PERU | Signature | 28/06/1919 | |
| PERU | Ratification | 10/01/1920 | |
| PERU | Withdrawal | 08/04/1939 | |
| POLAND | Signature | 28/06/1919 | |
| POLAND | Ratification | 10/01/1920 | |
| PORTUGAL | Signature | 28/06/1919 | |
| PORTUGAL | Ratification | 08/04/1920 | |
| ROUMANIA | Signature | 28/06/1919 | |
| ROUMANIA | Ratification | 14/09/1920 | |
| ROUMANIA | Withdrawal | 10/07/1940 | |
| SALVADOR | Accession | 10/03/1920 | |
| SALVADOR | Withdrawal | 10/08/1937 | |
| SERB-CROAT-SLOVENE STATE | Signature | 28/06/1919 | |
| SERB-CROAT-SLOVENE STATE | Ratification | 10/02/1920 | |
| SIAM | Signature | 28/06/1919 | |
| SIAM | Ratification | 10/01/1920 | |
| South Africa | Signature | 28/06/1919 | |
| South Africa | Ratification | 10/01/1920 | |
| SOVIET UNION | Withdrawal | 14/12/1939 | |
| SPAIN | Accession | 10/01/1920 | |
| SPAIN | Withdrawal | 08/05/1939 | |
| SWEDEN | Accession | 09/03/1920 | |
| SWITZERLAND | Accession | 08/03/1920 | |
| UNITED KINGDOM | Signature | 28/06/1919 | |
| UNITED KINGDOM | Ratification | 10/01/1920 | |
| UNITED STATES OF AMERICA | Signature | 28/06/1919 | |
| URUGUAY | Signature | 28/06/1919 | |
| URUGUAY | Ratification | 10/01/1920 | |
| VENEZUELA | Accession | 03/03/1920 | |
| VENEZUELA | Withdrawal | 10/07/1938 | |