Since 1973, applicants can apply for a European patent. European patents are granted by the European Patent Office, which is independent of the Eropean Union. The European patent is based on the European Patent Convention (EPC), which is ratified by 38 member states, including Norway, Switzerland and Turkey. Recently, agreements for for a Unitary Patent ("European patent") for EU states were agreed on. This unitary patent can be chosen by a patent assignee after the grant of the European patent (by the European Patent Office). An advantage of the Unitary patent would be its validity in the entire EU, whereas th European patent (granted by the European Patent Office) applies for the individual EPC member states. This implies that infringement and (in)validity in relation to the Unitary patent can be challenged for the entire EU in one go, whereas for the European patent this has to be dealt with in individual EPC member states.
However, not all 28 EU members which are (still) member of the EU will ratify these Unitary patent agreements At least Croatia and Spain will not ratify. This implies that after grant of the European patent there will be at least three patent systems: for states within the EU that have ratified, for states within the EU that have not (yet) ratified, and for non-EU states. Next to that, there are of course the EPC-member states that are non-EU members. For entry into force of the Unitary patent agreements, it is essential that France, Germany and the United Kingdom ratify. Until the Brexit, the Unitary patent agreements seemed to enter into force in 2017. However, ratification by the UK is now at least questionable.