| Country | Action | Action Date | Effective Date |
|---|
| Australia | Signature | 10/09/1919 | |
| Australia | Ratification | 16/08/1920 | |
| Canada | Signature | 10/09/1919 | |
| Canada | Ratification | 16/08/1920 | |
| FRANCE | Signature | 10/09/1919 | |
| FRANCE | Ratification | 29/07/1921 | |
| India | Signature | 10/09/1919 | |
| India | Ratification | 16/08/1920 | |
| ITALY | Signature | 10/09/1919 | |
| ITALY | Ratification | 15/12/1920 | |
| JAPAN | Signature | 10/09/1919 | |
| JAPAN | Ratification | 25/01/1921 | 14/10/1920 |
| New Zealand | Signature | 10/09/1919 | |
| New Zealand | Ratification | 16/08/1920 | |
| SERB-CROAT-SLOVENE STATE | Accession | 05/12/1919 | |
| SERB-CROAT-SLOVENE STATE | Ratification | 16/07/1920 | |
| South Africa | Signature | 10/09/1919 | |
| South Africa | Ratification | 16/08/1920 | |
| UNITED KINGDOM | Signature | 10/09/1919 | |
| UNITED KINGDOM | Ratification | 16/08/1920 | |
| UNITED STATES OF AMERICA | Signature | 10/09/1919 | |