The validation of a European patent in a contracting state is determined by Article 65 EPC, the London Agreement on the application of Article 65 EPC and the contracting state's national law. Hence, validation of a European patent in a contracting state may require the filing of a translation of the European patent as granted into one of the official languages of the contracting state, generally within three months from the date on which the mention of the grant of the European patent is published in the European Patent Bulletin.