Estonia ratifies the UPC Agreement on 1st August 2017. In that way, Estonia becomes the 13th country ratified the agreement along with Austria, Belgium, Bulgaria, Denmark, Estonia, Finland, France, Italy, Luxembourg, Malta, Netherlands, Portugal, and Sweden.
To be entered into force, the UPC Agreement have to be ratified by Germany and the UK too.
In the case of Germany, the ratification was suspended by the German constitutional court whereas in the UK the procedure was delayed by the Brexit and all uncertainties that followed.
More information can be found here.
Source: Lexology.