The London Agreement, which has been in force since 2008, is an optional treaty linked to the European Patent Convention (EPC).
It aims to reduce translation costs when validating European patents in states that are parties to the agreement.
On April 9, 2025, Montenegro acceded to the London Agreement. This measure entered into force for that country on August 1, 2025, making Montenegro the 23rd State party.
Since that date:
- No full translation into Montenegrin is required if the patent is granted in English or accompanied by an English translation in accordance with Article 65(1) EPC
- A translation of the claims into Montenegrin remains mandatory, however.
These rules do not apply to patents granted before August 1, 2025, even if they are subsequently amended in opposition, appeal, or limitation proceedings.
A similar system already exists for unitary patents, which is also designed to reduce translation costs.
