| Country | Action | Action Date | Effective Date |
|---|
| Australia | Signature | 10/09/1919 | |
| Australia | Ratification | 31/07/1920 | |
| BELGIUM | Signature | 10/09/1919 | |
| BELGIUM | Ratification | 31/07/1920 | |
| Canada | Signature | 10/09/1919 | |
| Canada | Ratification | 31/07/1920 | |
| ETHIOPIA | Declaration | 27/09/1923 | |
| FRANCE | Signature | 10/09/1919 | |
| FRANCE | Ratification | 23/07/1921 | |
| India | Signature | 10/09/1919 | |
| India | Ratification | 31/07/1920 | |
| ITALY | Signature | 10/09/1919 | |
| ITALY | Ratification | 14/04/1931 | |
| JAPAN | Signature | 10/09/1919 | |
| JAPAN | Ratification | 06/04/1922 | |
| New Zealand | Signature | 10/09/1919 | |
| New Zealand | Ratification | 31/07/1920 | |
| PORTUGAL | Signature | 10/09/1919 | |
| PORTUGAL | Ratification | 07/10/1922 | |
| South Africa | Signature | 10/09/1919 | |
| South Africa | Ratification | 31/07/1920 | |
| UNITED KINGDOM | Signature | 10/09/1919 | |
| UNITED KINGDOM | Ratification | 31/07/1920 | |
| UNITED STATES OF AMERICA | Signature | 10/09/1919 | |
| UNITED STATES OF AMERICA | Ratification | 29/10/1934 | |