In the EU Member States having ratified the UPCA, the Unified Patent Court has primarily exclusive competence for civil proceedings relating to conventional European patents, new unitary patents, supplementary protection certificates (SPCs) and European patent applications. During a transitional period of at least seven years, actions for infringement or for declaration of invalidity may additionally be brought before national courts.

Owners of or applicants for a conventional European patent granted or applied for before the end of this transitional period will have the possibility to exclude the competence of the Unified Patent Court with regard to this patent, or the corresponding application, for its entire term (so-called "opt-out"). Thus, the national courts of the EU member states participating in the UPCA continue to retain their exclusive competence. The condition for an opt-out is that no action has previously been brought before the Unified Patent Court in respect of the corresponding IP right. The opt-out can be withdrawn at any time (so-called "opt-in"), provided that no action has previously been brought before one of the said national courts.

A request for opt-out must be filed directly with the Unified Patent Court and becomes effective upon entry in a register created for this purpose.

The decision whether existing or future conventional European patents, or applications therefor, should fall under the competence of the Unified Patent Court, or should better remain under the old system, will generally depend on the individual needs of the proprietor or applicant. However, due to the fact that there is still no practical experience with the Unified Patent Court (June 2023), an opt-out will have to be considered in many cases, especially with regard to the predictability of the outcome of proceedings and costs.