| Country | Action | Action Date | Effective Date |
|---|
| Australia | Signature | 27/11/1919 | |
| Australia | Ratification | 09/08/1920 | |
| BELGIUM | Signature | 27/11/1919 | |
| BELGIUM | Ratification | 09/08/1920 | |
| BULGARIA | Signature | 27/11/1919 | |
| BULGARIA | Ratification | 09/08/1920 | |
| Canada | Signature | 27/11/1919 | |
| Canada | Ratification | 09/08/1920 | |
| CHINA | Signature | 27/11/1919 | |
| CUBA | Signature | 27/11/1919 | |
| CZECHOSLOVAKIA | Signature | 27/11/1919 | |
| CZECHOSLOVAKIA | Ratification | 16/04/1921 | |
| FRANCE | Signature | 27/11/1919 | |
| FRANCE | Ratification | 09/08/1920 | |
| GREECE | Signature | 27/11/1919 | |
| GREECE | Ratification | 04/09/1920 | |
| HEJAZ | Signature | 27/11/1919 | |
| India | Signature | 27/11/1919 | |
| India | Ratification | 09/08/1920 | |
| ITALY | Signature | 27/11/1919 | |
| ITALY | Ratification | 09/08/1920 | |
| JAPAN | Signature | 27/11/1919 | |
| JAPAN | Ratification | 26/05/1921 | |
| New Zealand | Signature | 27/11/1919 | |
| New Zealand | Ratification | 09/08/1920 | |
| POLAND | Signature | 27/11/1919 | |
| PORTUGAL | Signature | 27/11/1919 | |
| PORTUGAL | Ratification | 07/10/1922 | |
| ROUMANIA | Accession | 04/09/1920 | |
| SERB-CROAT-SLOVENE STATE | Signature | 27/11/1919 | |
| SERB-CROAT-SLOVENE STATE | Ratification | 16/08/1920 | |
| SIAM | Signature | 27/11/1919 | |
| SIAM | Ratification | 09/08/1920 | |
| South Africa | Signature | 27/11/1919 | |
| South Africa | Ratification | 09/08/1920 | |
| UNITED KINGDOM | Signature | 27/11/1919 | |
| UNITED KINGDOM | Ratification | 09/08/1920 | |
| UNITED STATES OF AMERICA | Signature | 27/11/1919 | |