Germany: Challenging and Defending EPO Patents

Last Updated: 23 October 2001
Article by Hendrik Wichmann


In a perfect world, there would be no disputes with your competitors about patents. The patent offices would grant patents on your inventions, and there would be a common understanding that patents are respected or are designed around. In the real world, things are different. Especially when you are used to the American patent system which still provides only (very) limited possibilities for challenging patent applications or patents before the patent office, you might be surprised to find yourself in one of the following situations: (A) Your European patent application or patent is attacked by one or more of your competitors; (B) You are planning to put your product on the European market or to produce same in Europe, and your freedom-to-operate analysis reveals that a "dangerous" European patent application or patent is pending; (C) In a special case of both scenarios, you and your competitor even made largely overlapping inventions, and the conflict cannot be solved in any sort of European interference procedure. This article will give you some general ideas of how to deal best with these scenarios.

Interference with the Examination Procedure

When strictly monitoring a competitor’s patenting activities, very often it is clear from the just published patent application that it may hinder or block your business activities, if granted. In such a case, it is worthwhile to consider whether this relevant application should already be attacked in European examination proceedings by filing Third Party Observations (3PO) under Article 115 of the European Patent Convention (EPC) or whether you should wait and analyze the patent upon acceptance and possibly oppose it. By filing 3PO, it is possible to influence the competitor’s claim or even to inhibit the granting of a patent by directing the examiner’s attention to particular facts or prior art references detrimental to patentability. Further upsides are: (i) the competitor’s legal position can be undermined before he has an enforceable patent (claims for injunction !); (ii) the effects may be immediate as compared to Opposition and subsequent Appeal Proceedings which may often take more than five years; (iii) you do not have to reveal your identity as compared to the usual situation in Opposition Proceedings (OP); and (iv) no official fee is incurring in contrast to the filing of an opposition (Euro 613,-). Possible downsides are: (i) you are not a party of the proceedings. Therefore, you may "participate" in the written procedure, but you are excluded from the oral procedure; (ii) there is a certain risk of "spoiling" ones argument, particularly if, due to time pressure, the arguments are not fully elaborated and sufficiently supported by evidence. Once an argument has failed to convince the examiner, it might be difficult to demonstrate its relevance in later OP.

Advice for observing party: 1. File, if you have a reasonable or strong argument for lack of clarity/support by the description (Art. 84 EPC; similar to 35 USC 2nd and 1st para.) or novelty (Art. 54 EPC). 2. File, if pending claims are relevant to you but introduce new matter (Art.123 (2) EPC), whereas the claims, as supported by the original disclosure, would not be infringed or would allow you to design around them. 3. File as early as possible, i.e. before the examiner sticks to his/her view of the case. 4. Do not file, if your novelty attack is weak or your only obviousness attack (Art. 56 EPC) is mediocre; save it for a later Opposition. 5. In case of a competitor’s patent application having superior priority (elder right) which largely overlaps with your own younger application, you may attack "undercover", but you should avoid such items as prior art objections which may backfire on your own case.

Advice for applicant: 1. Bring the application into a form "ready to grant" as soon as possible, and consider whether you can divide out anything that may cause a significant delay. 2. Use (informal) telephone conversations and interviews to communicate with the examiners and to speed up the procedure. 3. Be prepared that your granted patent will be opposed.

Challenging a European patent in Opposition vs. Nullity Proceedings

Opposition Proceedings (OP) are an effective and economic means to have the validity of a patent re-examined, because a successful opposition will cause the European patent to be revoked with respect to all designated Contracting States. This is in contrast to Nullity Proceedings which have to be initiated in (and only have effect for) each single designated state (Art. 138 (1) EPC), which results in much higher costs and a much reduced chance of overall success. While there may be cases where national Nullity or combined Infringement/Nullity Proceedings may be preferable (e.g., may provide higher chances that a particular European patent will be revoked), OP before the EPO are generally a straightforward matter. In opposition cases, an average of 30% of the patents are revoked, 38% are maintained in amended form, and only 32% are maintained as granted, i.e. the oppositions are rejected. The success rate of the opponents thus being fairly high, it is surprising that only limited use is made of this legal instrument (in 2000, the average opposition rate was 5.7% of the granted patents).

Opposition Proceedings are Independent and Contentious Proceedings between Parties

Following the examination procedure, the filing of a Notice of Opposition sets a separate and particular administrative procedure in motion. The OP are contentious proceedings between parties, i.e. the Proprietor and the Opponent(s), who represent opposite interests, and should be given equal treatment. (Thus, OP are not unlike US infringement proceedings, but normally much less tough and time-consuming, i.e. costly.) The Opponent may be "any person" without specifying any particular legal interest in the revocation of the opposed patent. The Proprietor, however, is not allowed to oppose his own patent (until reissue-like centralized European proceedings to restrict the claims will be available in 4-5 years, the Proprietor has to initiate limitations in each of the national parts of the European "bundle" patent). A Notice of Opposition may be filed within 9 months after grant of the patent (Art. 99 (1) EPC). Irrespective of the expiration of the opposition period, a party may intervene in a pending Opposition (or Appeal) Proceedings within 3 months after institution of infringement proceedings or proceedings for a court ruling that the alleged infringer does not infringe the patent-in-suit by filing a Notice of Intervention (Art. 105 EPC). If you are not (yet) party to a pending OP, you may nevertheless influence its outcome by supporting the Opponent(s) and/or by filing Third Party Observations pointing out further deficiencies. To be effective, the latter should certainly be right to the point, properly supported, and, preferably, not in contradiction with the Opponent(s) observations. The parties in OP normally have to cover their own costs, but on occasion the OD can force one party to pay the entire or partial costs incurred during taking of evidence or in Oral Proceedings of the other party (e.g. in case of late canceling of Oral Proceedings, abuse of procedure, etc.).

Content of the Notice of Opposition

The Notice of Opposition has to include a written reasoned statement of the grounds for opposition. An exhaustive list of grounds is given in Art. 100 EPC: The claimed subject matter is not new, is obvious, falls within a category excluded from being a patentable invention, is contrary to "ordre public" or morality, is not susceptible of industrial applicability; the specification does not contain sufficient disclosure of the invention for it to be carried out; and the subject matter of the granted patent goes beyond the original disclosure. The grounds are thus identical to the patentability provisions applied in the Examination procedure, but do not include the unity requirement (Art. 82 EPC), nor the requirements under Art. 84 EPC (clarity and support by the description). Nevertheless, Art. 84 EPC plays a role in the OP, if objections to either clarity or support arise from the amendments to the granted patent. Furthermore, clarity or support of one of the features used for defining the claimed subject matter may be taken into account in the examination of novelty or enablement. It is recommended to cite and properly support as many grounds for opposition as possible, and to object to all claims. This is due to the fact that in OP the examination is generally confined to the parts of the patent contested by the Opponent, and the grounds put forward by him. A more extensive examination will only be undertaken by the Opposition Division (OD), if facts have surfaced which clearly partially or entirely prejudice the maintenance of the patent.

Subsequent Procedure and Oral Proceedings

Initially, OP are conducted in writing with all parties concerned, developing arguments in full, and the Proprietor submitting amended patent documents to meet the grounds of opposition put forward, if necessary. In the great majority of cases, OP will result in Oral Proceedings before the OD. The OD consists of three technical examiners usually including the primary examiner involved in the granting procedure. In case of specific legal issues, a fourth, legally qualified examiner enlarges the OD. Several months before Oral Proceedings the OD issues a summons along with a communication listing the crucial issues to be discussed at the hearing. The summons also sets a date for submitting final observations and amendments (usually 1-2 months before the hearing) after which additionally filed facts, evidence and/or amended claims may be disregarded. Therefore, it is not advisable to hold back decisive information until the hearing in order to support your defense or attack. At the hearing, the patentability requirements at issue are usually dealt with one by one, and after all parties have been heard to each point, a decision is generally made immediately by the OD. The decision in writing, which triggers the deadlines for appeal, is normally shared with the parties within 3 - 6 months after the hearing.

Advice for Opponent: 1. General Strategy: What is the essential reason for opposing the patent? Are there any products (current or future) that may be affected by the patent? Consider the best case and the second best case scenarios: Will you have freedom-to-operate, will a (cross-) license be available to you or will you be able to design around it? Consider the worst case scenario: Avoid harming your own rights. 2. Start with your preparations several months before expiration of the opposition period: (i) Obtain a complete copy of the file wrapper including the priority document(s) and the prior art cited in the Search Report(s). (ii) Complete your prior art collection by checking the art cited in any counterpart in the US (where information disclosure requirements apply), by performing additional searches, etc. (iii) Make sure that the relevant art is really pre-published (evidence available?). 3. Investigate whether the new matter bar, Art. 123 (2) EPC, has been complied with (surprisingly often it is not !). 4. The burden of proof that the patent is invalid is on you (!): (i) Do not built your case only on lack of novelty over prior use or implicit/inherent disclosure. (ii) Prepare a strong case for obviousness. (iii) Base your case for lack of enablement on verifiable facts and back them up by evidence.

Advice for Proprietor: 1. Evaluate the importance of the patent: Does it cover any of your (current or future) products or is it used for defensive purposes? Does it provide leverage on your competitors? 2. General strategy: Consider the strengths of the Opponent(s) arguments in the light of the strengths and weaknesses of your patent. Then work out several lines of defense (i.e. amended sets of claims) gradually reduced in scope. Get these approved by your management and any licensees etc. so as to avoid a later change of strategy. 3. Take the "human element" into account: To convince the OD, tell the "story" of your patent, and back it up by additional beneficial data, if applicable. 4. Double-check your main claims: Apply the broadest reasonable interpretation of the features, and see whether they are still novel and enabled over the whole scope. 5. Avoid having the inventor(s) making (risky) statements at the hearing (he/she is neither the notional "skilled person" nor a patent attorney !).

Appeal Proceedings

Any party adversely affected by the decision may lodge an appeal with the Board of Appeal. The Appeal Proceedings (AP) are entirely separate and independent from the first-instance proceedings, and shall give a judicial decision on the correctness of the OD´s decision. To ensure that no fresh case is presented in AP, there are some procedural and material limitations, while the course of action is essentially the same as in OP. As to the outcome of the AP, there is one crucial aspect: Whereas the Proprietor may have lost his patent forever, the Opponent may still attack the patent in national Nullity Proceedings, if he is not satisfied with the decision of the Board of Appeal.

© 2001 by Dr. Hendrik Wichmann. First published in MIP Litigation Yearbook 2001, London, 2001.

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.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

Some comments from our readers…
“The articles are extremely timely and highly applicable”
“I often find critical information not available elsewhere”
“As in-house counsel, Mondaq’s service is of great value”

Related Topics
Related Articles
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of

To Use you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions