| Country | Action | Action Date | Effective Date |
|---|
| BELGIUM | Signature | 10/12/1956 | |
| BELGIUM | Acceptance | 27/01/1958 | |
| FRANCE | Signature | 10/12/1956 | |
| FRANCE | Acceptance | 26/07/1957 | |
| GERMANY FEDERAL REPUBLIC | Signature | 10/12/1956 | |
| GERMANY FEDERAL REPUBLIC | Acceptance | 13/09/1960 | |
| GERMANY FEDERAL REPUBLIC | Statement | 13/09/1960 | |
| ITALY | Signature | 10/12/1956 | |
| ITALY | Acceptance | 15/01/1959 | |
| ITALY | Statement | 15/01/1959 | |
| Land Berlin | Extension | 13/09/1960 | |
| LUXEMBOURG | Signature | 10/12/1956 | |
| LUXEMBOURG | Acceptance | 28/07/1958 | |
| NETHERLANDS THE | Signature | 10/12/1956 | |
| NETHERLANDS THE | Acceptance | 17/11/1958 | |
| UNITED KINGDOM | Signature | 10/12/1956 | |
| UNITED KINGDOM | Ratification | 31/07/1957 | |
| UNITED KINGDOM | Acceptance | 31/07/1957 | |