EP Validation is a system that allows a European patent granted by the European Patent Office (EPO) to take effect in states that are not full members of the European Patent Convention (EPC). It is a key part of international patent strategy for companies seeking protection in markets beyond Europe through a single, centrally processed application.
EP Validation is based on bilateral agreements between the European Patent Organisation and individual states. It allows the effects of a European patent to be extended to a validation state without a separate national patent application. Once validated, the patent has the same legal effect as a nationally granted patent in that state.
When an applicant pays the validation fee within the prescribed time limit, the European patent application can be validated in that state, and the subsequently granted patent obtains national patent effect there. Rights, infringements, invalidations, and proceedings are governed by that country’s national law — without the applicant needing to repeat the examination process at a national office. The EPO highlights that the system offers high legal certainty, cost-effective market protection, consistent examination quality, and a simpler procedure than separate national applications.
The EPO uses two related but distinct terms. The Extension system is an older arrangement for non-EPC states within Europe; today, Bosnia and Herzegovina is its only active participant. The Validation system, available since 2010, is newer and extends cooperation to countries outside Europe as well.
Validation is currently possible in the following states:
Costa Rica signed a validation agreement in December 2024, though it has not yet entered into force.
Every European patent application is automatically treated as a validation request for all states with which a validation agreement is in force on the filing date — no separate formal request is needed. The essential step is paying the validation fee on time.
The fee must generally be paid within six months of publication of the European search report, or in Euro-PCT applications, by the deadline for entry into the European phase — whichever is later. If the fee is not paid on time, the validation request is deemed withdrawn. In some cases, a two-month grace period is available with a 50% surcharge.
A validated European patent has the same effect as a national patent, is governed by national patent law, and any infringement or invalidity actions are handled by national courts. While examination is centralised at the EPO, enforcement remains national.
Validation states may also have their own translation requirements, publication rules, and renewal fees. Validation often requires translating the patent claims — and sometimes the full specification — into the local language.
For patent holders, a single European application can cover multiple countries without separate national examinations, reducing the need for local attorneys, individual examination fees, and parallel application processes. Patents are examined to EPO standards, considered among the world’s highest, and the system enables protection in fast-growing markets outside Europe.
For validation states, the EPO also emphasises the system’s development impact: participating countries benefit from technical cooperation, patent office training, IT development, judicial education, and stronger local innovation ecosystems. The system also reduces the volume of foreign national filings, freeing up local office resources.
Validation also applies within international PCT applications, provided the EPO is designated for a European patent, the validation state is designated for a national patent in the PCT application, and the validation agreement was in force on the international filing date.
EP Validation concerns states outside the EPC, is based on bilateral agreements, and produces national patent effects. The Unitary Patent applies to UPC member states within Europe, creating uniform protection across multiple EU countries. The UPC is a common patent court for Europe. These systems operate in parallel but on different legal foundations.
New validation agreements are continuously being negotiated. The Costa Rica agreement shows the system is expanding beyond Europe, reflecting the EPO’s broader ambition to strengthen its role as a global — not merely European — patent system.
Understanding EP Validation is essential for building an effective international patent strategy. If you need guidance on validation decisions or broader patent protection, contact our patent specialists to discuss your situation and develop an optimal approach.