Following the deposit of its instrument of accession on 9 April 2025, Montenegro officially became the 23rd contracting state to the London Agreement on 1 August 2025. This development significantly streamlines translation requirements for European patents validated in Montenegro and minimises procedural complexity.

Key provisions:

• The translation of the patent specification into Montenegrin is no longer required if the European patent is granted in English or accompanied by an English translation.
• A Montenegrin translation of the claims remains mandatory.
• The simplified rules do not apply to patents granted before 1 August 2025 that are subsequently amended through opposition, appeal, or limitation procedures.

Montenegro’s accession supports broader efforts to reduce costs and administrative burdens for patent holders across Europe, aligning its IP system more closely with international standards.