| Country | Action | Action Date | Effective Date |
|---|
| AUSTRIA | Signature | 20/12/1957 | |
| AUSTRIA | Ratification | 30/10/1959 | |
| BELGIUM | Signature | 20/12/1957 | |
| BELGIUM | Ratification | 22/07/1959 | |
| DENMARK | Signature | 20/12/1957 | |
| DENMARK | Ratification | 23/05/1959 | |
| FRANCE | Signature | 20/12/1957 | |
| FRANCE | Ratification | 23/02/1959 | |
| GERMANY FEDERAL REPUBLIC | Signature | 20/12/1957 | |
| GERMANY FEDERAL REPUBLIC | Ratification | 22/07/1959 | |
| GREECE | Signature | 20/12/1957 | |
| ICELAND | Signature | 20/12/1957 | |
| IRELAND, REPUBLIC OF | Signature | 20/12/1957 | |
| ITALY | Signature | 20/12/1957 | |
| ITALY | Ratification | 03/04/1963 | |
| LUXEMBOURG | Signature | 20/12/1957 | |
| LUXEMBOURG | Ratification | 19/05/1961 | |
| NETHERLANDS THE | Signature | 20/12/1957 | |
| NETHERLANDS THE | Ratification | 09/07/1959 | |
| NORWAY | Signature | 20/12/1957 | |
| PORTUGAL | Signature | 20/12/1957 | |
| PORTUGAL | Ratification | 26/09/1959 | |
| SPAIN | Accession | 22/07/1959 | |
| SWEDEN | Signature | 20/12/1957 | |
| SWITZERLAND | Signature | 20/12/1957 | |
| TURKEY | Signature | 20/12/1957 | |
| TURKEY | Ratification | 20/07/1959 | |
| UNITED KINGDOM | Signature | 20/12/1957 | |
| UNITED KINGDOM | Ratification | 09/05/1958 | |