| Country | Action | Action Date | Effective Date |
|---|
| ALBANIA | Signature | 10/06/1925 | |
| Barbados | Accession | 26/10/1926 | |
| Bermuda | Accession | 26/10/1926 | |
| British Guiana | Accession | 03/03/1927 | |
| British Honduras | Accession | 26/10/1926 | |
| Ceylon | Accession | 26/10/1926 | |
| Cyprus | Accession | 26/10/1926 | |
| Falkland Islands | Accession | 24/12/1926 | |
| Fiji | Accession | 26/10/1926 | |
| Gold Coast | Accession | 26/10/1926 | |
| Hong Kong | Accession | 24/12/1926 | |
| Jamaica | Accession | 26/10/1926 | |
| Leeward Islands | Accession | 26/10/1926 | |
| Malta | Accession | 26/10/1926 | |
| Mauritius | Accession | 26/10/1926 | |
| Nigeria | Accession | 26/10/1926 | |
| Northern Rhodesia | Accession | 26/10/1926 | |
| Nyasaland | Accession | 26/10/1926 | |
| Seychelles | Accession | 26/10/1926 | |
| Sierra Leone | Accession | 26/10/1926 | |
| St Helena | Accession | 26/10/1926 | |
| Straits Settlements | Accession | 26/10/1926 | |
| Tanganyika | Accession | 26/10/1926 | |
| The Gambia | Accession | 26/10/1926 | |
| UNITED KINGDOM | Signature | 10/06/1925 | |
| Windward Islands | Accession | 26/10/1926 | |