| Country | Action | Action Date | Effective Date |
|---|
| BELGIUM | Signature | 14/04/1957 | |
| BELGIUM | Ratification | 11/03/1959 | |
| DENMARK | Accession | 28/08/1974 | 01/09/1974 |
| FINLAND | Application | 06/01/1995 | |
| FRANCE | Signature | 14/04/1957 | |
| FRANCE | Ratification | 14/05/1959 | |
| GERMANY FEDERAL REPUBLIC | Signature | 14/04/1957 | |
| GERMANY FEDERAL REPUBLIC | Ratification | 02/12/1965 | |
| GERMANY FEDERAL REPUBLIC | Notification | 02/12/1965 | |
| GREECE | Accession | 20/05/1987 | 01/09/1987 |
| GREECE | Declaration | 20/05/1987 | |
| IRELAND, REPUBLIC OF | Accession | 25/08/1972 | 01/09/1972 |
| ITALY | Signature | 14/04/1957 | |
| ITALY | Ratification | 22/02/1960 | |
| Land Berlin | Extension | 02/12/1965 | |
| LUXEMBOURG | Signature | 14/04/1957 | |
| LUXEMBOURG | Reservation | 14/04/1957 | |
| LUXEMBOURG | Ratification | 20/11/1959 | |
| NETHERLANDS THE | Signature | 14/04/1957 | |
| NETHERLANDS THE | Ratification | 19/05/1960 | |
| PORTUGAL | Accession | 31/03/1987 | 01/09/1987 |
| SPAIN | Accession | 31/08/1986 | 01/09/1986 |
| SWEDEN | Application | 16/02/1995 | |
| UNITED KINGDOM | Accession | 30/08/1972 | 01/09/1972 |