| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| Barbados | Accession | 14/04/1928 | |
| British Guiana | Accession | 14/04/1928 | |
| British Honduras | Accession | 14/04/1928 | |
| Ceylon | Accession | 14/04/1928 | |
| Cyprus | Accession | 14/04/1928 | |
| Falkland Islands | Accession | 14/04/1928 | |
| Fiji | Accession | 14/04/1928 | |
| Gold Coast | Accession | 14/04/1928 | |
| Grenada | Accession | 14/04/1928 | |
| Hong Kong | Accession | 14/04/1928 | |
| India | Accession | 05/03/1928 | |
| Jamaica | Accession | 14/04/1928 | |
| Leeward Islands | Accession | 14/04/1928 | |
| Malay States, Federated | Accession | 14/04/1928 | |
| Malay States, Unfederated | Accession | 14/04/1928 | |
| Malay States, Unfederated | Accession | 16/05/1928 | |
| Malta | Accession | 14/04/1928 | |
| Mauritius | Accession | 14/04/1928 | |
| Nigeria | Accession | 14/04/1928 | |
| Northern Rhodesia | Accession | 14/04/1928 | |
| Nyasaland | Accession | 14/04/1928 | |
| Seychelles | Accession | 14/04/1928 | |
| SIAM | Signature | 14/07/1925 | |
| SIAM | Ratification | 26/12/1925 | |
| SIAM | Denunciation | 05/11/1936 | 04/11/1937 |
| St Helena | Accession | 14/04/1928 | |
| St Lucia | Accession | 14/04/1928 | |
| St Vincent | Accession | 14/04/1928 | |
| Straits Settlements | Accession | 14/04/1928 | |
| Tanganyika | Accession | 14/04/1928 | |
| The Gambia | Accession | 14/04/1928 | |
| UNITED KINGDOM | Signature | 14/07/1925 | |
| UNITED KINGDOM | Ratification | 16/12/1925 |