| Country | Action | Action Date | Effective Date |
|---|
| AUSTRIA | Signature | 22/04/1950 | |
| BELGIUM | Signature | 22/04/1950 | |
| DENMARK | Signature | 22/04/1950 | |
| FRANCE | Signature | 22/04/1950 | |
| GERMANY | Signature | 22/04/1950 | |
| GREECE | Signature | 22/04/1950 | |
| ICELAND | Signature | 22/04/1950 | |
| IRELAND, REPUBLIC OF | Signature | 22/04/1950 | |
| ITALY | Signature | 22/04/1950 | |
| LUXEMBOURG | Signature | 22/04/1950 | |
| NETHERLANDS THE | Signature | 22/04/1950 | |
| NORWAY | Signature | 22/04/1950 | |
| PORTUGAL | Signature | 22/04/1950 | |
| SWEDEN | Signature | 22/04/1950 | |
| SWITZERLAND | Signature | 22/04/1950 | |
| TRIESTE UK-US ZONE | Signature | 22/04/1950 | |
| TURKEY | Signature | 22/04/1950 | |
| UNITED KINGDOM | Signature | 22/04/1950 | |