Granted European Patent is valid as a regular national patent on the territory of each designated country provided that validation procedure has been conducted. Validation is a process of filing the corresponding request to the designated country, preparing the translation into the national language, and payment of the maintenance fees.

The London Agreement is a patent law agreement launched in London on 17, October 2000 aimed at minimisation of translation costs for European patents granted under the European Patent Convention (EPC).

Subsequently, countries where the official language is English, French or German are no longer required to provide the translation for the validation process. Countries where the official language is not English, French or German, should provide a translation into one of these languages. Additionally, translation of claims in one of their official languages might be required.

At the same time, all member states retain the right to require the translation of patent specifications into their official language in case of any dispute.

The European patent is valid automatically on the territory of Belgium, Germany, France, Switzerland, Liechtenstein, Monaco, Ireland, Luxembourg and the United Kingdom. It is necessary to conduct the procedure of validation if the applicant wishes to obtain patent protection in other European Convention member states.

Validation of a European patent should be performed in such member states of the European Patent Convention as Austria, Bulgaria, Cyprus, Croatia, Czech Republic, Denmark, Estonia, Spain, Finland, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, North Macedonia, Malta, Montenegro, the Netherlands, Norway, Poland, Portugal, Romania, Sweden, Slovenia, Slovakia, San Marino, Turkey, as well as in Albania, Serbia. The effect of a European patent can be extended to Bosnia and Herzegovina which is not party to the EPC but has signed extension agreements with EPO.

The European Patent Organization signed validation agreements with Morocco, the Republic of Moldova, Tunisia and Cambodia in 2010, 2013, 2014 and 2017 correspondingly. European patents filed on or after March 1, 2015, can be validated in Morocco. Validation of European patents filed on or after November 1, 2015, is possible in Moldova. As of December 1, 2017, European patents can be validated in Tunisia obtaining the same scope of protection as national patents in Tunisia. European patents, filed on or after March 1, 2018, can be validated in Cambodia. Validation of European patents filed on or after January 15, 2024, is possible in Georgia.