In principle, the EPC has universal jurisdiction over all European Patents.
There is an exception: Within a seven-year transitional period infringement and nullity proceedings are also possible before national courts
There is also a counter-exception: For a specific IP right, an owner can declare to exclude the jurisdiction of the EPC.

During the transitional period (seven years) without opt-out the UPC has jurisdiction without exception, national courts have additional jurisdictionan .

Prerequisite for an opt-out:

- A declaration must be filed no later than one month before the end of the transition period, The declaration and the Opt-Out must be registered

- No action has been brought before the UPC

Withdrawal from opt-out (=opt-in) is possible (unlimited in time, no "opt-out-again" possible)

Effect of the opt-out: only national courts are responsible.