On 3 June 2016, Bulgaria became the tenth country to complete its ratification formalities.

Bulgaria joins Finland, Portugal, Luxembourg, Malta, Denmark, Belgium, Sweden, France and Austria as one of the ten countries who have all deposited instruments of ratification of the UPC Agreement with the General Secretariat of the Council of the EU.

The unitary patent system requires 13 countries to ratify, including the UK, France and Germany, meaning that just the UK, Germany and one other country are required to ratify to bring the unitary patent system into effect. Preparations are still on track for the unitary patent system to come into force in Spring 2017 (as long as Britain does not vote to Leave the EU on 23 June 2016).