| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| Ascension Island | Accession | 12/05/1931 | |
| Bahamas | Accession | 12/05/1931 | |
| Barbados | Accession | 12/05/1931 | |
| Bermuda | Accession | 12/05/1931 | |
| British Guiana | Accession | 12/05/1931 | |
| Cayman Islands | |||
| Cyprus | Accession | 12/05/1931 | |
| Falkland Island Dependencies | Accession | 12/05/1931 | |
| Falkland Islands | Accession | 12/05/1931 | |
| Gold Coast | Accession | 12/05/1931 | |
| Jamaica | |||
| JAMAICA | |||
| North Borneo | Accession | 12/05/1930 | |
| ROMANIA | Signature | 06/08/1930 | |
| Sarawak | Accession | 12/05/1931 | |
| Sierra Leone | Accession | 12/05/1931 | |
| St Helena | Accession | 12/05/1931 | |
| Straits Settlements | Accession | 12/05/1931 | |
| Tanganyika | Accession | 12/05/1931 | |
| Trinidad And Tobago | Accession | 12/05/1931 | |
| Turks And Caicos Islands | |||
| UNITED KINGDOM | Signature | 06/08/1930 | |
| UNITED KINGDOM | Ratification | 01/12/1930 |