The Transitional Period and the UPC: Coordinating Two Judicial Orders

For seven years from 1 June 2023, two judicial orders decide cases on the same classic European patents. Article 83 of the Agreement leaves patentees and defendants a choice between the Unified Patent Court and the national courts, and allows a patentee to withdraw its titles from the Court's competence by an opt-out that can be reversed at any time. This duality was meant to be a transition. It has become a field of manoeuvre.

What Article 83 actually organises

The transitional period opens shared jurisdiction for European patents without unitary effect, leaves national proceedings pending at its end unaffected, and may be extended by a further seven years by decision of the Administrative Committee, after consultation and an opinion of the Court. The opt-out may be filed up to one month before the period expires, and its withdrawal takes effect once entered in the register.

In other words, the timetable is not locked and forum strategy stays open throughout the period. For a European portfolio, an opt-out is not a defensive reflex to be decided once and for all, but a judgment call to be revisited as the case law develops.

Lis pendens is not enough

Regulation 1215/2012 governs lis pendens and related actions between courts of Member States, and treats the UPC as a court common to several of them. In practice the mechanism meets three limits.

First, identity of parties dissolves within corporate groups: a subsidiary sued before a local division is not formally the same party as the parent company sued in Paris or Milan. Second, no alert signals in real time, from one order to the other, that a parallel action exists. Third, no obligation requires the parties to disclose proceedings pending elsewhere.

The result is familiar to practitioners: a stay is never automatic, and the coexistence of proceedings becomes a tactical instrument rather than an accident, as we analysed in our piece on parallel litigation before the UPC.

EU law as the point of contact

Coherence between the two orders runs through EU law. Opinion 1/09 of the Court of Justice set the requirement: a court applying EU law must preserve its autonomy and uniform interpretation. Articles 21 and 22 of the Agreement organise cooperation with the Court of Justice and the liability of Member States for breaches, with no timetable and no expedited procedure.

Two recent decisions have brought the two orders together more effectively than the texts. In BSH Hausgeräte v Electrolux of 25 February 2025 (C-339/22), the Grand Chamber widened the possibility for a national court to rule on infringement of foreign patents. And on 6 March 2026 the UPC Court of Appeal referred questions to the Court of Justice for the first time, in Dyson v Dreame, on the extent of its jurisdiction over defendants established outside the Union. The dividing line between national courts and the unified court is now being drawn in Luxembourg, as we set out in our analysis of the UPC's first preliminary reference.

What still has to be built

Three measures lie with the Administrative Committee or with practice, without amending the Agreement. An automatic alert in the register, telling the other divisions and the national courts that an action has been brought on the same patent, would remove most of the blind spots. An obligation to disclose parallel proceedings, backed by costs consequences, would usefully replace the goodwill of the parties. An expedited referral route, finally, would allow questions to be put to the Court of Justice without freezing the proceedings on the merits.

None of this removes competition between forums, which is a feature of the system. It would only make outcomes less dependent on the order in which the actions were brought.

Key takeaways

• The transitional period under Article 83 of the Agreement runs for seven years from 1 June 2023 and may be extended by a further seven.
• An opt-out remains possible until one month before the period expires, and its withdrawal takes effect once entered in the register.
• The lis pendens rules of Regulation 1215/2012 are ill-equipped for corporate groups and for the absence of any alert between courts.
• The BSH v Electrolux and the UPC's first reference place the Court of Justice at the junction of the two orders.
• A register alert, a duty to disclose parallel proceedings and an expedited referral route would reduce fragmentation without amending the Agreement.

Frequently asked questions

How long does the UPC transitional period last?

Seven years from 1 June 2023, that is until 1 June 2030, and the Administrative Committee may decide to extend it by a further seven years.

Can an opt-out still be filed?

Yes, until one month before the transitional period expires, provided no action has already been brought before the UPC on the patent concerned.

Is an opt-out final?

No. The patentee may withdraw it at any time, the withdrawal taking effect once entered in the register. An action already brought before a national court does, however, close that option.

Must a national court stay proceedings if the UPC is seised of the same patent?

Not automatically. The rules on lis pendens and related actions apply, but they require an identity of parties and subject matter that corporate structures often defeat.

Dhenne Avocats designs forum and opt-out strategies for European portfolios, before the French courts and before the Unified Patent Court. Talk to us.

This article is an original and substantially updated adaptation of an analysis by Matthieu Dhenne first published on the Kluwer Patent Blog on 16 June 2025: Legal Inception: Harmonizing the UPC and the National Courts through EU Law.