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 an important part of international patent strategy for companies seeking broad protection through a single, centrally processed application.
EP validation is based on bilateral agreements between the European Patent Organisation and individual states. The system allows the effects of a European patent to be “extended” to a validation state without requiring a separate national patent application. Once validated, the patent has the same legal effect in that state as a nationally granted patent.
The EPO highlights that the validation system offers high legal certainty, cost-effective market entry, consistent examination quality, and a simpler procedure compared to separate national applications.
Normally, a European patent can be validated in EPC member states after grant. The validation system extends this possibility to countries outside the EPC. When an applicant pays the validation fee within the prescribed time limit:
It is important to distinguish EP validation from related systems. The Extension system is an older arrangement for non-EPC European states — Bosnia and Herzegovina is currently the only active extension state. The Validation system is newer and not limited to Europe. Neither should be confused with the Unitary Patent or the Unified Patent Court (UPC), which operate on different legal foundations within Europe.
Validation is currently available in the following states:
Costa Rica signed a validation agreement in December 2024, though it has not yet entered into force. New agreements are continuously being negotiated, reflecting the EPO’s ambition to strengthen its role as a global patent system.
Every European patent application is automatically considered a validation request for all states with which a validation agreement is in force on the filing date. No separate formal request is needed for each country.
The critical step is paying the validation fee on time. The fee must generally be paid within six months of the publication of the European search report, or — for Euro-PCT applications — within the time limit for entry into the European phase, whichever expires later. If the fee is not paid on time, the validation request is deemed withdrawn and the right to validation in that state is lost. In some cases, a two-month grace period is available with a 50% surcharge.
Once validated, the patent has the same effect as a national patent in that state and is applied in accordance with national patent legislation. Infringement and invalidation actions are handled before national courts. Although the patent is examined centrally by the EPO, enforcement remains national.
Validation states may have their own translation requirements, publication rules, and national renewal fees. Validation often requires translating the patent claims — and sometimes the entire patent publication — into the local language.
For patent holders, a single European patent application can cover a large number of countries without separate national examinations, reducing the need for multiple local patent attorneys, separate examination fees, and parallel application processes. Patents are examined to EPO standards, widely regarded as among the highest in the world, and the system provides access to protection in fast-growing markets outside Europe.
For validation states, the EPO emphasises the system’s development impact. Participating countries benefit from technical cooperation, patent office training, IT system development, and the strengthening of local innovation ecosystems. In many countries, the system also reduces the volume of foreign national applications, freeing up local office resources for domestic innovation.
Validation also operates within international PCT applications, provided that 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.
Effectively managing your EP validation strategy — whether through direct European applications or the PCT route — requires careful planning and an understanding of both EPO procedures and the national requirements of each target state. For personalised advice, contact our experienced team to discuss your specific requirements and develop a cost-effective protection strategy.