Is the system mandatory

For Unitary Patents, the UPC will be the only venue for litigation concerning infringement and invalidity.

For European patents, during a transitional period, the UPC will be an optional venue (alongside national courts) for infringement and validity litigation unless the patent has been opted out of the UPC by the patentee. The transition period will last for seven years after the commencement of the UPC with the possibility that it will be extended for up to a further seven years.

For national patents, national courts remain the only venue for litigation.