Registering unitary effect of European patents- what can go wrong?

1. Introduction

The unitary effect of European patents under Regulation (EU) No 1257/2012 and Regulation (EU) No 1260/2012, launched in 2023, represents a major step towards the simplification of patent protection in the European Union. Instead of validating a European patent separately in multiple countries, proprietors can request that their patent, granted by the European Patent Office (EPO), receive unitary effect as provided in Article 142 of the European Patent Convention (EPC). This results in a single patent covering eighteen of the twenty-eight participating EU Member States. The scope of the unitary effect is intended to be  the whole EU in future, yet at the time of writing this article, such a development is not yet foreseeable.

The procedure for registering unitary effect upon request to the EPO is designed to be straightforward, and EPO data confirm that more than 99% of requests are successful. Nevertheless, a small proportion still fail. Some of these failures are avoidable, while others result from legal or procedural limitations.

The author follows the EPO’s weekly announcements of decisions rejecting requests for unitary effect and reviews the reasons. A few of his observations (including file numbers to enable detailed analysis) are shared below.

2. High success rate

The EPO’s statistics[1] clearly show that the system works efficiently in practice. As of 2025-10-15, 70,222 requests for unitary effect had been filed; among those 660 were rejected. The figures for 2024—the only full calendar year of the system so far—are similar: 28 050 requests were submitted, and 71 were rejected.

3. Simple criteria

The criteria for obtaining unitary effect are clearly defined in the EPO Rules relating to Unitary Patent Protection (UPR[2]), which, in Rules 5 and 6, implement the EU Regulations. In principle, there are only a few basic requirements:

1. Timing – The request for unitary effect must be filed within one month from the date of publication of the mention of grant in the European Patent Bulletin (i.e. the date of publication of the B1 document).
2. Uniformity of claims – The patent must have been granted with the same set of claims for all participating Member States.

• Translation – The proprietor must file a full translation of the patent specification into one official EU language other than the language of the proceedings before the EPO.
  • For example, if the proceedings were in English, the translation must be into French, German, Polish, Spanish, or any other official EU language.

1. Formal requirements – The request must be properly signed and correctly indicate the European patent number and complete data of the patent proprietor. The easiest way to verify compliance is to consult EPO Form 7040[3] or Rule 6(2) UPR.

In 2024, an additional negative indicator was introduced due to sanctions related to the war in Ukraine: unitary effect is not available to patent proprietors based in the aggressor country, Russia.

4. What Can Go Wrong?

4.1 Late filing

The one-month deadline for filing the request is non-extendable, but it may be re-established if due care is demonstrated. If the requester fails to demonstrate due care, the request for unitary effect will be rejected.

4.2 Missing translations

Some representatives file the request without a translation when the patent proprietor is still undecided, knowing that the EPO will note the deficiency and invite them to remedy it by setting a further one-month time limit. This practice is apparently used at times as a way to extend a deadline that is otherwise non-extendable.

If the patent proprietor eventually decides not to proceed, the translation is never filed and the request for unitary effect is rejected[4]. Clearly, there are also unintentional failures, although these appear to be infrequent[5].

4.3 Lack of uniformity of claims

There are several reasons why a granted patent may not have uniform claims, including:

• Claims amended by patent proprietor in some participating Member States only, to avoid earlier national prior rights;
• Withdrawal of designation of a participating Member State by the patent proprietor;
• Impossibility of designation of a participating Member State — the so-called “Malta effect”[6];
• Partial transfers of patents concerning only some of the participating Member States.

4.31 Tricky divisional applications

It might seem easy, in theory, to ensure that a patent is designated in the same states and that it maintains an identical set of claims across all contracting states. In practice, however, this can be more complex. Some decisions are separated by long time intervals, and some are taken in different procedures.

An example is patent EP3970521, granted for the subject matter of application EP21198049.5, which was a divisional application of the parent application EP19787177.5. EP3970521 was refused unitary effect in 2024 because of actions taken by the applicant in the parent application in 2021—namely, the withdrawal of the designation of Germany.

The request for the divisional application was filed less than two months after the withdrawal of the designation. Had the orderbeen reversed, the unitary patent could have been granted, and the EPO would not have raised an objection regarding the uniformity requirement.

4.3.2  Status of the Great Britain

The term “participating Member States,” as defined in Article 2(a) of Regulation (EU) No 1257/2012, is apparently interpreted by the EPO as no longer encompassing the United Kingdom. Consequently, for some patents in which the designation of GB had been withdrawn, unitary effect was nevertheless registered.

There is a certain logic to this interpretation, as the United Kingdom is no longer an EU Member State, let alone a participating Member State, and Article 2(a) explicitly refers to the time of the request for unitary effect as the relevant moment for determining participation.

4.4 Sanctions against Russia

It seems that the ban on registering unitary effect is not particularly bothersome to citizens of the country targeted by sanctions. However, a few EPO decisions can be found rejecting unitary protection on the grounds of Rule 5(2)(b) UPR[7].

4.5 Representation

The unitary effect requested by an authorized employee for EP3740733 was ultimately registered. Nevertheless, the EPO initially found the authorization insufficient within the meaning of Article 9(1) of Regulation (EU) No 1257/2012, issued an invitation to correct the deficiency, and then failed to process the second authorization submitted in response.

The decision to reject unitary effect was apparently disregarded, and the EPO eventually registered unitary effect, leaving the public uncertain as to which legal framework was applied to waive or supersede the initial decision.

5 Conclusion

The procedure for registering unitary effect has a success rate as high as any in the patent system, yet it can still take unexpected turns.

[1] https://www.epo.org/en/about-us/statistics/statistics-centre#/unitary-patent

[2] https://www.epo.org/en/legal/up-upc/2022/upr.html

[3] https://link.epo.org/communications/F7040E.pdf

[4] EP19709030.1 is an example of invitation to remedy deficiencies being ignored.

[5] EP20734475.5 is an example in which translation was first incomplete, than filed late.

[6] EP18179060.1 – failed to designate Malta and Latvia

[7] The registration of unitary effect because of sanctions was rejected e.g. for EP3236478, EP3626072 and EP3572126.