According to the website of the Council of the European Union (and just about every other official IP channel), the UK deposited its instrument of ratification (on 26 April 2018) to become the 16th country to complete its ratification formalities. The UK joins Latvia, Lithuania, Estonia, Italy, the Netherlands, Bulgaria, Finland, Portugal, Luxembourg, Malta, Denmark, Belgium, Sweden, France and Austria as one of the sixteen countries who have completed their ratification processes.
The unitary patent system requires 13 countries to ratify, including the UK, France and Germany. However, the German Constitutional Court challenge has thrown the timescale and the long term future of the unitary patent system into doubt.
There are now enough countries to have ratified the unified patent court agreement that the system will come into effect if Germany completes its own ratification procedures and sufficient approvals to the PPA are obtained.
Mark Richardson 27 April 2018