| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| Australia | Extension | 15/12/1920 | |
| Canada | Extension | 15/12/1920 | |
| DENMARK | Signature | 05/07/1920 | |
| DENMARK | Ratification | 15/12/1920 | |
| FRANCE | Signature | 05/07/1920 | |
| FRANCE | Ratification | 15/12/1920 | |
| India | Extension | 15/12/1920 | |
| ITALY | Signature | 05/07/1920 | |
| ITALY | Ratification | 15/12/1920 | |
| JAPAN | Signature | 05/07/1920 | |
| JAPAN | Ratification | 15/12/1920 | |
| New Zealand | Extension | 15/12/1920 | |
| South Africa | Extension | 15/12/1920 | |
| UNITED KINGDOM | Signature | 05/07/1920 | |
| UNITED KINGDOM | Ratification | 15/12/1920 |