| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| Cameroons | Extension | 27/02/1928 | |
| Nauru | Extension | 27/02/1928 | |
| New Guinea | Extension | 27/02/1928 | |
| Palestine, Mandated Territories (exc. Trans-Jordan) | Extension | 27/02/1928 | |
| SIAM | Signature | 05/01/1928 | |
| South West Africa | Extension | 27/02/1928 | |
| Tanganyika | Extension | 27/02/1928 | |
| Togoland | Extension | 27/02/1928 | |
| UNITED KINGDOM | Signature | 05/01/1928 | |
| Western Samoa (UK) | Extension | 27/02/1928 |