By March 1, 2021, the Convention had been ratified by the following (38) States:
- Albania*
- Austria
- Belgium
- Bulgaria
- Croatia*
- Cyprus
- Czech Republic
- Denmark*
- Estonia
- Finland*
- France*
- Germany*
- Greece
- Hungary*
- Iceland*
- Ireland*
- Italy
- Latvia*
- Liechtenstein*
- Lithuania*
- Luxembourg*
- Malta
- Monaco*
- Netherlands*
- North Macedonia*
- Norway*
- Poland
- Portugal
- Romania
- San Marino
- Serbia
- Slovakia
- Slovenia*
- Spain
- Sweden*
- Switzerland*
- Turkey
- United Kingdom*.
Extension of a European Patent (2 States): Bosnia and Herzegovina, Montenegro.
Validation of a European Patent (4 States): Cambodia, Moldova, Morocco, Tunisia.
* Members of the London Agreement (21 States).