The interplay between EPO and national proceedings may take various forms. The Technical Board of Appeal revoking a European Patent during European-wide litigation is one of the more dramatic examples. The EPO’s stay of the grant of an application following an entitlement claim (an ‘entitlement torpedo’) another one. And then there is the central limitation procedure…

According to Article 105a EPC the patentee can request the EPO to limit a European Patent by an amendment of the claims. Article 68 EPC determines that a European Patent shall be deemed not to have had “from the outset” the rights conferred by the patent to the extent it has been limited in the limitation proceedings. These three words, “from the outset”, are words that matter in national proceedings. The long lasting proceedings between High Point and KPN before the Dutch courts show why.


To – not so briefly – summarize 12 years of litigation (well, part thereof):

In 2009 KPN filed a nullity action with District Court The Hague as regards High Point’s patent for a “Wireless access telephone-to-telephone network interface architecture”. High Point responded with an infringement action. The court nullified the patent, and dismissed the infringement claim, in 2010.

On appeal before the Court of Appeal The Hague, High Point filed a deed limiting the patent’s claims. This was done after KPN had already filed its defense statement against High Point’s statement of appeal. In a 2015 interlocutory judgment the CoA refused the deed (and thus the limited claims) on the basis of the so-called ‘two conclusion rule’. This national procedural rule prescribes, in short, that in appeal proceedings an appeal statement and defense statement are filed, and (therewith) puts a limitation on when appeal grounds/defenses can still be submitted. In view of this due process rule, the CoA refused the limited claims, and decided that the proceedings should be continued on the basis of the patent in the form in which it was granted and several auxiliary requests filed with High Point’s appeal statement.

High Point’s supreme appeal against the interlocutory decision was rejected by the Supreme Court on 13 September 2017. The case was referred back to the CoA to continue the appeal proceedings.

High Point informed the CoA in October 2017, that during the supreme appeal proceedings, the EPO had limited the patent in central limitation proceedings (on 7 September 2017).

The CoA, despite the central limitation having effect “from the outset” (ex tunc), did not substantively consider the limited “B3” version. The CoA considered that, in view of the central limitation, the originally granted “B1” version no longer existed and, in view of article 68 EPC, should be regarded as never having existed in that broad form. The District Court’s decision that the patent in the broad – B1 – form was invalid, should therefore be upheld. The CoA considered High Point’s argument that the patent is valid in the centrally limited form to be contrary to due process. In short, the centrally limited claims were considered almost identical to the limited claims which the CoA had refused before, while the supreme appeal against this refusal was dismissed. Allowing a debate on the validity of the B3 version, would effectively circumvent this supreme decision. High Point was (still) too late to start this debate. According to the CoA, the right conferred on High Point by the EPC to limit its patent centrally does not preclude national procedural law restrictions on the reliance on a central limitation of a patent.

High Point appealed the CoA’s decision to the Supreme Court, again. In a February 2020 judgment, the Supreme Court dismissed High Point’s appeal (decision in Dutch available here). Interpreting Articles 68 and 105a-105c EPC in view of articles 31-32 of the Vienna Convention, the Supreme Court, inter alia, considered that the wording of these EPC provision does not suggest that the right conferred on the patent proprietor to apply for a central restriction of his patent precludes the national court, in proceedings pending before it, from disregarding an application for such a central restriction on the ground that it is contrary to the requirements of due process. The context of these provisions, and object and purpose of these objections, do not point in a different direction. Moreover, the history of the drafting of Articles 68 and 105a-105c EPC show that the central restriction procedure before the EPO could coincide with proceedings before the national court concerning the validity of that patent. It was noted that the central limitation procedure does not take precedence over the national procedure, and that it is national procedural law that determines whether proceedings pending there must be stayed or may continue. The European limitation procedure does not take precedence over (nullity) proceedings before national courts and is not exclusive. Also, in other EPC contracting states it is accepted that national procedural law determines whether reliance on a centrally limited patent is admissible in already pending national proceedings.

One of High Point’s complaints before the Supreme Court was that the CoA confirmed the District Court’s decision without a substantive assessment of the validity of the centrally limited patent, (arguably) resulting in the nullification of that limited patent without the District Court or CoA having assessed its validity. In response the Supreme Court considered as follows (emphasis added):

“This complaint rightly takes as a starting point that only the assessment of the validity of the patent in its broader form [the patent as granted – author] was presented to the district court, but overlooks the fact that the court of appeal disregarded High Point’s reliance on the central limitation of the patent on account of a violation of due process, which means that the court of appeal – just like the district court – did not get around to a substantive assessment of the validity of the patent in its limited form [the centrally limited patent – author]. The upholding of the district court’s judgment is based on the consideration of the court of appeal (in section 2.2), which was not contested in cassation, that the patent in its broader form must, in view of art. 68 EPC, be deemed never to have existed, so that the final judgment of the district court on the invalidity of the patent in its broader form must be considered correct. It does not follow from the foregoing – contrary to what the complaint assumes – that the District Court or the Court of Appeal has nullified the patent in the limited form on the grounds of an assessment of the contents. The fact that High Point cannot rely on the patent in its limited form in these proceedings is therefore not the result of a substantive assessment and nullification of that patent, but merely arises from the procedural course of events in this case, in particular the time at which High Point invoked the central limitation of the patent. This does not affect the fact that both High Point and KPN are free, in principle, to still subject the validity of the patent in its limited form to a substantive assessment in new proceedings. Therefore, the complaint cannot lead to cassation.”

In other words: the CoA did not rule on the validity of the centrally limited patent. As a consequence, the centrally limited patent was not invalidated.

…and Back Again

The Supreme Court’s ruling opened up a new chapter in the litigation: in August 2020 High Point filed a new action against KPN with the District Court on the basis of the (limited) B3 version of the patent, claiming a declaration of infringement and damages (no injunction: the patent expired in 2012).

KPN requested High Point’s claims to be declared inadmissible/denied. KPN, in sum, argued that the B3 version did not enter into force for the Netherlands because before EPO’s central limitation on September 7, 2017, the B1 version was annulled by the District Court in 2010. This invalidation has direct effect on condition that the judgment becomes final in due course. This condition had been fulfilled, as the CoA upheld the 2010 District Court decision, while the supreme appeal was dismissed. The 2010 decision should therefore be considered res judicata in these new proceedings between the parties.

The District Court, in a May 12, 2021 decision, dismissed KPN’s request (decision in Dutch available here). The District Court considered that the condition mentioned by KPN is a suspensive condition. As long as the judgment has not yet become final, the patent still exists, but only its legal effects cannot be invoked. The 2010 decision has indeed become final, but considers the B1 version. However, at the time of the central limitation the patent had not yet been (finally) invalidated. Therefore, the doctrine of res judicata does not mean that it is also settled between the parties that the CoA, by upholding the 2010, has also ruled that the B3 version is null and void. The Supreme Court explicitly considered in its 2020 judgment that the Court of Appeal did not express an opinion on the content of that limited patent. The proceedings based on the B3 version will therefore continue.

The District Court considered that it would be undesirable and economically disadvantageous for the parties to have to spend time and money on conducting a substantive patent law debate if at a later point in time the CoA, or, however unlikely, the Supreme Court, might have a different opinion on the admissibility of High Point’s claims in these new proceedings. Therefore, the District Court granted the right to an interim appeal, which appeal may be brought directly before the Supreme Court.

The story therefore continues, in one way or another…


The author’s firm represents High Point in this case.


To make sure you do not miss out on regular updates from the Kluwer Patent Blog, please subscribe here.

Kluwer IP Law

The 2022 Future Ready Lawyer survey showed that 79% of lawyers think that the importance of legal technology will increase for next year. With Kluwer IP Law you can navigate the increasingly global practice of IP law with specialized, local and cross-border information and tools from every preferred location. Are you, as an IP professional, ready for the future?

Learn how Kluwer IP Law can support you.

Kluwer IP Law
This page as PDF


  1. Thankyou for sharing this very interesting case. It shows once again the devastating consequences of the EPO granting patents which aren‘t valid, and how a patentee can continue to uphold the status of legal uncertainty.
    In my humble opinion, a claimant who decides to enforce his patent and fails, should not be allowed a second shot with a limited version thereof.

  2. It is interesting to note that the problem will occur as well with the UPC, should it ever come.
    Facing a nullity action nothing withholds the proprietor to seek a limitation.
    At least the problem is solved at the EPO. In case of an opposition the proprietor is bared from limiting his patent. Any limitation could only be filed during the opposition procedure!

  3. What I’m looking for is a balance between the legitimate interests of the patent owner and those of the Party accused of infringement. I like to think that the courts in The Netherlands will find whatever balance the law allows them to find.

    There is in English law a concept called “equity” meaning “fairness”. It is available, for example, to refuse a patent owner an amendment to the patent, when the petition to amend is filed carelessly, mischievously, disingenuously or unfairly late. What constitutes “too late”? The court of equity decides that.

    But if the EPC is written in such a way that it’s never “too late” for the patent owner to narrow the patent, no matter how egregious its behaviour or litigation tactics, then this is the sort of mischief that patent owners and their zealous lawyers will inevitably plot and execute, as a matter of course, if that’s what it takes to win the case.

    BREXIT is a disaster, and let’s not dwell on the UK PM, the “Irish Question” and reneging on an International Agreement signed only months ago, but one good thing about Brexit is that the English courts will henceforth have more freedom to administer The Rule of Law equitably. And that’s very important for public acceptance of the Rule of Law, in any jurisdiction.

    1. Max, you write about the rule of law. It is somewhat sad that the EBA seems to have decided that the rule of law can be so widely construed that white can be black and vice versa. Read the latest decision (G4/19) and, I hope, you will be gob-smacked.

      1. G 4/19 is indeed somehow surprising.
        Explaining that Art 125 is about procedural rules but is at the same time about substantive law is rather surprising.
        I would have said double patenting is for the contracting states to decide and not for the EPO.
        Concluding that because of the travaux préparatoires there was a will to forbid double patenting although no decision has been taken is far fetched.
        Since G 2/19 it seems that the EBA is deciding so as to please the management of the office! The reform of 2016 has rendered the boards less independent than before.

        1. Part of a world-wide trend, Attentive?


          And see what the US Supreme Court has just done, appointing the USPTO Chief Executive in the seat of judgement on the decisions of the judges of the PTAB.

        2. G 4/19 seems to “forget” Art. 52(1) EPC:

          European patents SHALL (not MAY) be granted for any inventions, in all fields of technology, provided that they are new, involve an inventive step and are susceptible of industrial application.

          I believe that Art. 172 EPC is really urgent now.

          1. Such a Diplomatic Conference should be preceded by a Conference of ministers in charge of IP of the contracting states which should take place every five years, cf Art 4a.

            In view of the manifest enthusiasm of the presidents in place since 2010, it do not think that we will see Art 172 being applied in the near future. and yet after the conference of 2000 there was a second basket dealing with substantial law.

            However, this means opening Pandora’s box, and possibly coming up with a reform of the BA, this time giving them real independence and not merely increasing the perception of their independence.

            The EPC is silently amended on the one hand by the rules of procedure, cf. R 28(2) with the complicity of the EBA and its “dynamic interpretation” and the AC.
            On the other hand the EPC is amended by unilateral decisions of the resident of the 10th floor, there again with the complicity of the EBA and the AC, see New normal which could not exist without Art 15aRPBA20 and G1/21.

            Where have we seen a international convention can be amended in such a drastic way by secondary legislation, with the complicity of those who are meant to be the guardians of it.

            The EPO is really becoming a banana republic!

        3. Why, Attentive Observer, is the explanation surprising? Reference to point 665 of the minutes of the proceedings of the Main Committee I (concerning a request by the UK delegation) indicates that the prohibition of double patenting was understood as a principle of procedural law (only one European patent can be granted for the same invention in respect of which there are several applications with the same date of filing); deciding whether the claims of different applications claim the same invention is, however, a substantive matter.
          The situation is not dissimilar with Art. 123 EPC, cited in G 4/19 to explain why provisions in chapter I of Part VII can have such a dual nature: paragraph 1 of Art. 123 defines procedural rules (European patent applications and European patents may be amended in proceedings before the EPO; applicants – not patentees (see R 6/19, Reasons, no. 6-9) shall have at least one opportunity to amend the application); yet, paragraphs 2 and 3 of Art. 123 define substantive provisions.
          The results of the discussions recorded in the travaux préparatoires show that the matter was not felt to be for the contracting States only, doesn’t it?
          I generally agree with your acute remarks; this time, I do disagree.

          1. It is your good right to disagree and i respect your point of view.

            I still maintain my point that Art 125 is only to be applied for procedural rules. That some procedural rules can have an influence on the substance is clear, e.g. Art 13 RPBA20, but the reasoning of the BA in this matter failed to convince me.

            The problem of double patenting has not been solved in the travaux préparatoires, and it is only a kind of “dynamic” interpretation of those which lead to the conclusion that the member states wanted the prohibition of double patenting.

            A former assistant at CEIPI, working at the EPO, wrote a PhD thesis on the applicability of Art 125. It would be interesting to see what he said there.

            It remains that for me it is a problem for the contracting states to resolve.

  4. Dear Max Drei,

    I have a bit more balanced view. If for the opponent the time limit is the end of the 9 months, the proprietor better abide by the time limit under R 116(1). Any request filed and substantiated within this time limit is admissible.
    Anything coming after is also prima facie late beside a combination of granted claims. And limiting his claims with features from the description during op is in principle a no go.
    There might be situations in which the opponent can file new documents or the proprietor new requests, but they are rather limited and no more than keeping the balance between parties,
    And what has been missed by the proprietor (and by the opponent) can rarely be introduced in appeal.

  5. Attentive, when I wrote about narrowing the claims at the EPO, I was thinking not about oppositions but, rather, about initiation of limitation proceedings under Art. 105a. Is there any time limit on that? How about initiating such proceedings years after the commencement of infringement proceedings? Is that always OK?

    1. Good point: there should be a rule corresponding mutatis mutandis to Rule 93 EPC, which should allow third parties to file a request with the EPO (similar to Rule 14 EPC) to prevent limitation proceedings if nullity/infringement proceedings are pending before a national court (or the UPC).

  6. @ Max Drei,
    Sorry for my mistake! You have a point, but my reply to your point is what I say to Patent robot below here.
    I cannot see the EPC/EPO exerting such a direct influence in national infringement or nullity proceedings.
    @Patent robot,
    This is a matter for the national legislator or the national case law. Once the opposition period is over, the EPO loses any competence to discuss the fate of the national part of a European Patent.
    The EPO decided for procedures before it, but has no power to influence the procedure in a contracting state, or even later at the UPC. this could be done at the UPC by amending its RP, but for this the UPC has to exist.

    1. I mentioned limitation proceedings under Art. 105a/b EPC, which in my opinion are not “a matter for the national legislator or the national case law”: are they?

  7. @ Patent robot,
    Art 105a/b correspond indeed to the exceptional situation of the EPO regaining competence over the form of the patent, but not its fate, after the end of the opposition period.
    Please do not forget, the whole discussion here is whether the national judge could block an action in limitation before the EPO when the patent is challenged in nullity before a national court.
    And this clearly of the competence of the national legislator.

Comments are closed.