| Country | Action | Action Date | Effective Date |
|---|
| Barbados | Accession | 01/12/1928 | |
| British Honduras | Accession | 01/12/1928 | |
| Burma | Accession | 09/02/1929 | |
| Canada | Accession | 01/12/1928 | |
| Ceylon | Accession | 01/12/1928 | |
| Cyprus | Accession | 01/12/1928 | |
| GAMBIA THE | Accession | 01/12/1928 | |
| Gold Coast | Accession | 01/12/1928 | |
| Hong Kong | Accession | 01/12/1928 | |
| Malta | Accession | 01/12/1928 | |
| Nigeria | Accession | 01/12/1928 | |
| Palestine | Accession | 01/12/1928 | |
| Palestine | Reservation | 01/12/1928 | |
| Sierra Leone | Accession | 01/12/1928 | |
| SPAIN | | | |
| St Helena | Accession | 01/12/1928 | |
| Straits Settlements | Accession | 01/12/1928 | |
| Tanganyika | Accession | 06/08/1931 | |
| Trinidad And Tobago | Accession | 01/12/1928 | |
| UNITED KINGDOM | Signature | 05/04/1927 | |
| Windward Islands | Accession | 01/12/1928 | |