Review of Current Status of Post-Grant Opposition System in Comparison with Invalidation Trial System

One year has passed since the post-grant opposition system was reinstated on April 1, 2015, after a 12-year hiatus since 2003. The re-introduction of the post-grant opposition system has provided an alternative means to nullify a third party’s patent, in addition to the conventional patent invalidation trial system. This article summarizes the differences between these two systems and reviews the current situations thereof, as a guidance in determining which procedure to be chosen for specific cases.