EPO vs UPC: Procedural Considerations For EPO Oppositions And UPC Revocation Action Proceedings

Since the introduction of the UPC in 2023, parties challenging the validity of a European patent have, in many cases, had the option of filing an opposition before the EPO, filing a revocation action before the UPC, or pursing both in parallel. While each route offers a central mechanism for challenging patent validity in multiple jurisdictions, they operate on very different procedural timelines. This article compares the expected duration of opposition/revocation proceedings before the EPO and UPC, highlights key procedural differences, and summarises practical considerations for parties navigating European patent disputes.

Commencement

At the EPO, which covers 40 member states, an opposition must be filed within 9 months of grant of the European patent. Once that period has expired, validity can no longer be centrally challenged before the EPO. Until the introduction of the UPC, parties seeking to revoke a European patent after expiry of the opposition period were generally limited to the costly and time-consuming process of filing oppositions through the individual national courts.

The UPC now offers an alternative route. For European patents opted in to the UPC, which covers 18 of the 40 EPC member states, a revocation action can be filed at any time during the life of the patent. If successful, the patent is revoked, but only in the 18 UPC contracting states, though there has been case law to suggest that the UPC can decide on the validity of (but not legally revoke) a European patent in other EPC states with binding effect for the parties involved in the UPC action.

Target duration and procedural timelines

The UPC aims to deliver a decision on a revocation action within 12 months of filing. At the EPO, the overall process typically takes 2-3 years, depending on the complexity of the case and any delays caused by the parties. Both the EPO and UPC follow a written procedure followed by an oral hearing, however, in order to achieve the target 12-month duration, the UPC operates on a significantly tighter timetable.

The patent owner has two months to respond to a UPC revocation action, compared with four months to respond to an EPO opposition. The subsequent deadlines in the UPC proceedings are also generally shorter, meaning that parties need to prepare and progress their cases more quickly than in EPO opposition proceedings.

Key procedural differences

A key procedural difference in opposition/revocation procedures at the EPO and the UPC is the UPC’s ‘front-loaded’ approach. For revocation actions before the UPC, parties are required to present their complete case at the outset of proceedings. A strict approach is taken to amendments, which are only allowable for new developments that could not have been presented earlier. At the EPO, while new grounds for opposition cannot be added as of right after filing an opposition, they may be admitted at the opposition division’s discretion.

Therefore, a highly relevant document filed at a late stage is likely to be allowable before the EPO, but may be inadmissible before the UPC unless there is clear reason that the party could not have previously been aware of its existence.

A further key difference between oppositions before the EPO and revocation actions before the UPC is the admissible number of auxiliary requests. The UPC places a requirement that auxiliary requests be “reasonable in number in the circumstances of the case” (Rule 30.1(c) RoP). It is not possible to specify an exact number of auxiliary requests that would be considered reasonable. However, based on the case law, more than ten auxiliary requests appears likely to be considered excessive.

Before the EPO, there is no limit on the number of auxiliary requests which can be filed, providing more flexibility in their use in the defence of patent validity. The UPC’s front-loaded approach therefore requires parties to give greater consideration to their case and potential fallback positions at an early stage, whereas the EPO provides greater flexibility to develop these positions as the proceedings progress.

Practical considerations

Some practical points to consider when deciding the best strategy for opposing a European patent are outlined below:

1. Scope: An EPO opposition decision applies across more states than a UPC decision. However, the UPC provides a route to challenge validity across multiple jurisdictions once the EPO’s nine-month opposition period has expired.
2. Timelines and costs: There is a strict window in which to file EPO opposition, whereas a UPC revocation action can be brought at any time during the life of the patent. The UPC aims to deliver fast decisions, which may be key to cases of high commercial importance, but is associated with higher costs than the EPO. However, the UPC may offer a more cost-effective route where a challenge would otherwise need to be pursued before multiple national courts.
3. Case preparation: The front-loaded nature of UPC proceedings requires parties to set out their case at an early stage, which can require more extensive preparation upfront than an EPO opposition and allows for less flexibility in amending the case once proceedings have begun.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.