Opposition Systems

Many countries provide opposition mechanisms in their patent systems.  Opposition systems stricto sensu offer third parties an opportunity to oppose the grant of a patent within a certain period of time provided by the applicable law. 

An opponent must allege at least one of the grounds for opposition among those that are prescribed in the applicable law. Opposition procedures are closely related to the patent granting procedure. An opposition may be requested soon before the grant of a patent (pre-grant opposition) or after the grant of a patent (post-grant opposition).

In some countries, an opposition may be filed pre-grant, within a certain time period immediately after the publication of the application for a patent and before the examination phase, in which case the procedure resembles, to a certain extent, the so-called third party observation system.  It is possible to combine pre-grant and post-grant opposition systems.  India, for example, provides both a pre-grant and a post-grant opposition system.  One of the main objectives of the opposition system is to provide a simple, quick and inexpensive mechanism that ensures the quality and validity of granted patents by allowing an early rectification of invalid patents.  In general, opposition proceedings are inter partes procedures conducted before the patent office, not a court.

Pre-grant opposition often starts once the examination of a patent application has been completed by a positive result.  The Office publishes its intention to grant the patent on the claimed invention contained in the application, and provides a certain time period during which an opposition can be filed.  The opponent shall state the grounds for opposition and submit any evidence.  If no opposition is filed during that period, the patent will be granted.  If an opposition is filed, the applicant will be notified of that fact, together with the grounds for opposition and the evidence (for example, prior art documents that demonstrate lack of inventive step).  The applicant will be given the opportunity to comply with the requirements under the applicable law, and to make observations, within the prescribed time limit.  In accordance with the applicable law, the opponent has the possibility to respond to the observations made by the applicant.  Based on the submissions by the opponent and the applicant, an examiner or any other person entrusted to decide on opposition cases under the applicable law will make a decision as to whether the patent shall be granted or not.

In some countries, the pre-grant opposition system is designed in such a way that it starts after the publication of the patent application and before substantive examination.  Once the patent application is published, an opposition may be filed within a certain time period prescribed under the applicable law.  The opponent shall state the grounds for opposition and submit any evidence.  If no opposition is filed during that period, the substantive examination will be carried out.  If an opposition is filed, the applicant will be notified, and given an opportunity to make observations and/or amend the application within the prescribed time period.  The conclusion of the opposition will be notified to both the applicant and the opponent.

Post-grant opposition starts once the patent is granted.  Once the fact that a patent has been granted is published, an opposition may be filed with evidence within a certain time period prescribed in the applicable law.  Similar to the pre-grant opposition, the patentee will be notified about that fact, and be given the opportunity to comply with the requirements under the applicable law, and to make observations, within the prescribed time limit.  In accordance with the applicable law, the opponent has the possibility to respond to the observations made by the patentee.  Based on the submissions by the opponent and the applicant, whoever is entrusted to decide on opposition cases under the applicable law will make a decision as to whether the patent shall be maintained, amended or revoked.

Since one of the objectives of the opposition system is to provide a simple mechanism to ensure the quality and validity of granted patents, procedural and substantive requirements provided by the applicable laws regarding opposition systems have certain common aspects.  However, there are differences in the details.  Some of these differences are the following:

  • the timeframe during which an opposition may be filed:  the opposition period may start immediately after the publication of the patent application, after the completion of the substantive examination with a positive result and/or after the grant of the patent;
  • entitlement to file an opposition:  in many national laws, any party, including the applicant or the patentee, may file an opposition.  However, some laws provide that any third party (excluding the applicant or the patentee) may file an opposition;
  • the threshold for opposition:  in many countries the opponent has to provide full evidence of the grounds.  In one country, an opposition may be instituted if it is “more likely than not” that the patent is invalid;  with respect to admissibility, in some countries the request has to be sufficiently substantiated, provide written documents and other evidence while in other countries, the criteria of admissibility are not defined in their patent laws;
  • the disclosure of the identity of the requester:  in some countries, it is possible for the opponent, the true party in interest, not to disclose his identity, which may be in favor of continuing good business relationship between the opponent and the patent applicant or patentee;
  • the length of the opposition period:  the length of the opposition period varies from country to country.  In many countries, the duration may vary from two to six months for pre-grant opposition and from six to 12 months for post-grant opposition;
  • the grounds for an opposition:  in many countries, the requirements regarding novelty, inventive step, industrial applicability, sufficiency of disclosure and addition of new matter going beyond the original disclosure are grounds for an opposition.  Non‑compliance with the requirements concerning the exclusions from patentable subject matter also forms part of the grounds for an opposition in many countries.  Some countries accept an opposition on the grounds that an applicant/patentee is not entitled to the right to a patent, or on other grounds covering all requirements that should be fulfilled to obtain a patent.  They include, for example, the fact that information regarding corresponding foreign applications was not submitted, the source or geographical origin of biological material used in the invention was not disclosed, or the essential formalities were not complied with;
  • reviewing officers:  the opposition may be conducted by an examination division or the proceedings may be held before a special opposition board;  the board may include technical and legal examiners or judges;
  • inter partes procedural requirements:  formal and procedural requirements relating to, for example, a request, notification to parties, arguments, evidence, oral hearing and final decision depends on the applicable law, most likely based on the general civil procedural law of each country;
  • opposition fee:  in many countries, the payment of an opposition fee is required to file an opposition;
  • the effect of the opposition on civil actions:  in some countries the opposition has an estoppel effect or an effect for civil proceedings to stay.  In other countries both administrative and civil proceedings could be pursued independently and in parallel;  and
  • the timeframe for an opposition:  in one country the final determination has to be issued within one year, extendable up to six months;  in many countries, no time limits for a final administrative decision is specified.

An appeal against the final decision of the opposition body is generally possible, often to a court.  It should be noted that, according to Article 62.5 of the TRIPS Agreement, final administrative decisions in procedures concerning the acquisition and maintenance of intellectual property rights as well as the administrative revocation and inter partes procedures shall be subject to review by a judicial or quasi‑judicial authority. 

In a larger sense, the opposition system is complemented by related mechanisms which allow third parties to intervene in the patent examination process before the grant of a patent or to challenge the grant of a patent after its grant.  Those mechanisms are similar to the opposition system, but may differ in some criteria from the opposition system stricto sensu, which is a inter partes, time-bound review systems.  Three types of related mechanisms could be distinguished:

The patent system intends to promote innovation, dissemination and transfer of technology by granting a limited exclusive right to prevent others from using a patented invention without the consent of the patent owner and, at the same time, requiring the patent owner to fully disclose the invention to the public.  In order to meet this objective, the patent law lays down strict requirements, both procedural and substantive, to obtain patent protection.  Those requirements are fundamental to a functioning patent system, as they were created in order to ensure that only those inventions that are “worth” protecting for the purposes of facilitating innovation and meeting the broad public interest would obtain patent protection.

However, in reality, it may nevertheless happen that an invention that does not fully meet the requirements under the applicable law obtains a patent.  For example, since the patent examination process is conducted primarily ex parte, a substantive examiner may overlook a piece of prior art and inadvertently reach a positive decision regarding the patentability of the claimed invention.  Such a situation should not be necessarily considered as low quality examination in a given country, since the piece of prior art could be published in an exotic language or in an isolated publication.  Further, in some countries, only formality examination is conducted.  In order to rectify the grant of a deficient patent, in general, a patent revocation procedures are provided either before a competent court or before an administrative/quasi-judicial body the decision of which can be reviewed by a judicial body.  The opposition system provides an additional administrative layer of review that prevents the grant of invalid patents through the participation of third parties to the review process.  The idea is that the participation of third parties, who may be well informed about the technology concerned, would complement the resources available to the patent office, and would increase the credibility of granted patents.  The third parties could be, inter alia, competitors of the applicant or patentee having a good knowledge of the technological area concerned and who have their business interest in eliminating deficient patents.

Since the opposition procedure is provided just before or after the grant of the patent, it allows an early rectification of invalid patents.  The possibility to rectify invalid patents at an early stage is also beneficial for a patentee, since the patentee can have more trust in the validity of his patent.  Thus, a patent granted on an invention that has gone through opposition proceedings would be considered as having a higher credibility in terms of its compliance with novelty, inventive step and other requirements of patent law.

Compared to the review process before a court, the opposition system and related administrative mechanisms have various advantages.  They include:

  • the opposition procedure, which is an administrative process, is generally simpler, quicker and less expensive;
  • an opposition may be filed by any person (or any third party), while a patent revocation procedure in court may, in some countries, be initiated only by a party who fulfills certain conditions, for example, being an interested party or being adversely affected by the decision subject to the appeal.  Therefore, the opposition system takes into account the wider knowledge of the general public;  in addition, in some countries, the reviewing body may also consider the evidence not presented by the parties;
  • the decision of an opposition board is made by examiners and other officers with technical expertise, while a judge may not always be familiar with the technology concerned;
  • differently from litigation by courts in some countries, the patent applicant or patentee is given by the administrative body conducting the opposition an opportunity to narrow or amend the claims, in order to avoid the refusal or revocation of a patent application or patent;
  • the proceedings before an opposition board is considered to put less strain than revocation litigation to the relationship of parties, which might be partners in other research and development projects.  For example, in some countries, the third party might oppose anonymously to a patent or the procedure of submitting third party observations is largely documentary or conducted ex officio.

While the primary purpose of opposition systems is to ensure that patents are not granted to creations which do not meet the patentability requirements, they also target another important objective, which is to safeguard the scope of information in the public domain.  Although revocation proceedings are available, the grant of patents of unsatisfactory quality may have a limiting effect on the public domain.  In other words, once a patent is erroneously granted, the claimed invention, which otherwise would remain in the public domain, can be used by others only with the authorization of the patentee. 

Viewed from the angle of innovation policy, the positive effect of the patent system on innovation can only be achieved by valid patents complying with all the requirements of the applicable law.  Patent opposition procedures, along with other revocation procedures available under the national law, can be considered as one of the possible tools available in the patent system which supports the grant of valid patents.  It is in keeping with the broad policy objectives of the patent system and in the interest of various stakeholders, such as government, industry, academia, the patentees and third parties that patents are granted only to genuine inventions that meet all the requirements under the applicable law.  While the grounds for opposition may differ from country to country, the most common grounds provided under national laws, such as the lack of novelty, inventive step or industrial applicability and non‑compliance with the requirement of sufficient disclosure, are grounds that are often invoked by patent examiners to reject patent applications.  By ensuring a high credibility and validity of granted patents, the opposition mechanisms, along with other revocation procedures, mitigate the problem of cost that patents of unsatisfactory quality may create. In addition to high social cost, invalid patents create cost for patentees of such patents if the patentees need to spend resources in fighting off litigation involving patents with questionable validity.  Patents that meet all the requirements imposed by patent laws may be reliably enforced in court and licensed to others.  At the same time, such patents also provide the greatest value to the public and clarify the extent to which others may approach the protected invention without infringing it.

In order to set up an opposition procedure, the administration (the patent office) needs to have relevant resources, such as technically qualified examiners or other officers who will conduct the opposition proceedings.[1]  This could be relevant particularly for offices in developing countries which may have more difficulty in hiring technically qualified staff and have perhaps a more limited access to technological material on prior art to carry out substantive examination.[2]  In this context, it is recalled that the opposition procedures are closely related to the patent granting procedures.  Since high quality substantive examination requires human and financial resources, it seems that opposition systems are utilized in the national/regional patent granting procedures either as a supplementary mechanism to the substantive examination by examiners or as a complementary mechanism to substantive examination.  Taking the former approach, patent examiners are primarily tasked to conduct substantive examination, and only where they made affirmative decisions, the general public has the opportunity to supplement the examination shortly before or after the patent grant.  On the other hand, according to the second approach, the general public plays a complementary role in examining patent applications, thus “examining” published patent applications which have not been reviewed by patent examiners yet.  Different approaches are possible depending on the resources available in the patent office examination sector and in the general public, as well as on the allocation of tasks among different “agents” in order to provide an optimal examination/review mechanism.  It has been recommended for countries without substantive examination to inform the public about observations by third parties in the absence of opposition proceedings.[3]  Therefore, it is considered important that the patent law of each country explore various mechanisms which would allow detecting and challenging the grant of invalid patents at an early stage of the patent granting procedure, taking into account the available resources.

The opposition is subject to the payment of fee in most countries.  However, in general, such fee is not significant compared to patent litigation costs.[4]

Opposition fees are set by the national patent offices reflecting, in general, the marginal costs for the patent offices to review the applications or patents under opposition, and countries are free to make such procedures free of charge or to provide various flexibilities to various opponents, for example to natural persons or small and medium sized enterprises, if they wish to do so.  While, at the national level, various fee-related policies can be adopted by the patent offices, it is most likely that opponents should bear the cost of hiring professional advisors to assist them in preparing and filing the opposition case.  The fee related to hiring professional advisors is particularly relevant when the opponent is a national or resident of another country and, therefore, according to the national law, may be obliged to hire a local advisor to file an opposition.[5]

One of the major challenges in designing an opposition procedure is that it could delay the whole process of finalizing the grant of a patent.  Where a number of oppositions based on different items of prior art and on different grounds are filed, the applicant (or the patentee) shall argue against each opponent, and shall defend his invention.  Since anyone can file an opposition, a great number of oppositions could be filed in complex cases.[6] 

A pre‑grant opposition system supports legal certainty by allowing a pre-review of the patentability of an invention by third parties before granting the patent.  In other words, it increases the validity of granted patents.  However, the pre‑grant opposition introduces an additional period during which all the applications are pending before the patent office prior to the grant of the patents.  The statistical data show that, in practice, only a small number of applications are opposed.  Consequently, although it is a matter of several months, in general, there is an inevitable delay across the board in granting patents, including for applications which were not subject to opposition, for the period during which an opposition could be filed.  In a post‑grant opposition system, the delay will only be applicable, in principle, to those affected by oppositions and this does not have an impact on those patents not subject to any opposition.  However, while the post-grant opposition system does not extend the period between the filing of the application and the grant of the patent, during the opposition period, the enforceability of the opposed patent could be uncertain.  Another effect of the post‑grant opposition could be that such patents may not be considered of a high commercial value, since potential licensees may hesitate to enter into licensing agreement due to the uncertainty over the validity of the patent during the opposition period.

In short, policy makers need to consider two elements:  on the one hand, an additional review process may have a positive effect on the promotion of innovation by increasing the quality and the validity of granted patents.  On the other hand, such an additional process may delay the granting process and introduce a period of uncertainty as regards the enforceability of opposed patents and hold up licensing deals. 

The publication of relevant information, such as the publication of the patent application after 18 months from the filing date (or priority date) and/or the publication of the granted patent, is a prerequisite for pre-grant and post-grant opposition.  However, the scope of published information, for the purposes of opposition, may vary from one country to another, from the publication of all information contained in patent applications, including the detailed description of inventions, in some countries, to only the bibliographic data in other countries.  However, it is to be noted that even in those countries where only the bibliographic data is published, the patent offices make available to the public the full contents of patent applications or patents for inspection, and allowing third parties to access the entire applications or patents in the pre-grant or post-grant opposition context.[7]  In addition, easier access to prior art information by third parties will make it more easy for them to substantiate their opposition claim.

Even if a third party, often a competitor, has access to relevant information and has evidence that could be sufficient to file an opposition to prevent a patent to be granted or to revoke a granted patent, he may not necessarily launch the opposition in view of his overall business interest.  For example, a patent may be so trivial that it can easily be designed around.  Further, not every granted patent will be successfully commercialized and therefore might not be opposed to by competitors.  An opposition system is only one of the various mechanisms that support the patent administration in fulfilling the public policy objectives, and an effective opposition system can be designed only in connection with the patent‑granting procedures and other revocation mechanisms in a given country.

While national/regional opposition systems are different, in view of the above paragraphs, non‑exhaustive factors that may contribute to an enabling environment for an effective opposition system may include:

  • easy access to patent applications and patents that are laid open for opposition;
  • easy access to prior art information;
  • availability of human resources capable to conduct opposition procedures;
  • reasonable opposition timeframe which balances the interests of applicants/patentees and third parties;
  • reasonable formalities and procedures that allow effective conduct of opposition procedures, such as:
    • conduct of the inter partes procedures, including documentary and/or oral proceedings;
    • rules for the provision of supporting evidence and arguments;
    • composition of the opposition body that takes into account the policy objectives pursued by the opposition system;
  • grounds for opposition that balance the interest in quality of the patent system and legal certainty;
  • fee mechanisms;  and
  • rules on the interrelationship between opposition procedures and litigation.

Footnotes

1 As an alternative, a patent Office which does not have resources to conduct substantive review may conclude cooperation agreement with other offices. For information on such cooperation activities see Policy Guide on Alternatives in Patent Search and Examination PDF, Policy Guide on Alternatives in Patent Search and Examination

2 There are various projects undertaken by WIPO to improve access of developing countries to prior art databases. These initiatives are described in documents SCP/13/5 and SCP/14/3.

3 AIPPI, Yearbook 1991/I, pages 291-294.

4 For example, it was estimated that the patent litigation cost in Germany could be around EUR 50.000 (cost of 1st instance) and EUR 90.000 (cost of second instance) (See Communication from the Commission to the European Parliament and the Council, Enhancing the Patent System in Europe, Brussels, 3.4.2007, COM(2007)).  The fee for filing an opposition in Germany with DPMA is EUR 200.

5 Article 2(3) of the Paris Convention (and Article 3(2) of the TRIPS Agreement by reference to the Paris Convention), allows certain discrimination against nationals of other countries including in relation to the requirement that foreigners should appoint a local agent.

6 For example, the Oncomouse case (EP 0169672) received 17 oppositions, and Edinburgh/stem cells case (EP 0695351) received 14 oppositions.  A study shows that the likelihood of opposition increases with patent value, and that opposition is particularly frequent in areas with strong patenting activities and with high technical or market uncertainty.  (Dietman Harhoff, Markus Reitzig “Determinant of opposition against EPO patent grants - the case of biotechnology and pharmaceuticals”, International Journal of Industrial Organization, 22 (2004), 443-480).

7 Within the Program on Modernization of IP Institutions, WIPO have assisted national IP Offices in making their databases available to public through digitations of paper documentation.

No international treaty expressly regulates the substantive requirements with respect to various administrative revocation mechanisms such as opposition systems, re-examination procedures or other administrative revocation procedures available under the national/regional laws as such.  Countries are free to provide, or not to provide, such mechanisms in their national laws.  However, while substantive requirements are not dealt with in existing treaties, some general procedural requirements prescribed in the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS Agreement) and the Patent Law Treaty (PLT) may be applicable to such procedures.

TRIPS Agreement

Article 62.4 of the TRIPS Agreement provides that, where a Member’s law provides administrative revocation and inter partes procedures such as opposition, revocation and cancellation, they shall be governed by the general principles set out in Article 41.2 and 3.  Article 41.2 and 3 reads:

“2. Procedures concerning the enforcement of intellectual property rights shall be fair and equitable.  They shall not be unnecessarily complicated or costly, or entail unreasonable time-limits or unwarranted delays.

“3. Decisions on the merits of a case shall preferably be in writing and reasoned.  They shall be made available at least to the parties to the proceeding without undue delay.  Decisions on the merits of a case shall be based only on evidence in respect of which parties were offered the opportunity to be heard.”

Further, Article 62.5 states that final administrative decisions in the above procedures referred to under Article 62.4, including administrative revocation and inter partes opposition procedures, shall be subject to review by a judicial or quasi-judicial authority.  However, Article 62.5 further states that there shall be no obligation to provide an opportunity for such review of decisions in cases of unsuccessful opposition or administrative revocation, provided that the grounds for such procedures can be the subject of invalidation procedures.

In addition, as a general rule, according to Article 62.2, Members shall ensure that the procedures for grant, subject to compliance with the substantive conditions for acquisition of the right, permit the granting of the right within a reasonable period of time so as to avoid  unwarranted curtailment of the period of protection. 

Patent Law Treaty (PLT)

According to PLT Article 10(1), non-compliance with certain formal requirements with respect to an application may not be a ground for revocation or invalidation of a patent, either totally or in part, except where the non-compliance with the formal requirement occurred as a result of a fraudulent intention.  Those formal requirements are: 

  • form or contents of application (PLT Article 6(1)); 
  • formal requirements relating to request form, fees and priority document (PLT Article 6(2), (4) and (5)); 
  • form and means of transmittal of communications (PLT Article 8(1) and (3));  and
  • language and signature of communications (PLT Article 8(2) and (4)).  Accordingly, once a patent is granted by a PLT Contracting Party, it shall not be revoked or invalidated on the grounds of non-compliance with the above formal requirements. 

In addition, PLT Article 10(2) provides that a patent may not be revoked or invalidated, either totally or in part, without the owner being given the opportunity to make observations on the intended revocation or invalidation, and to make amendments and corrections where permitted under the applicable law, within a reasonable time limit.  PLT Article 10(2) applies to all proceedings for the revocation or invalidation of a patent.  It therefore applies to proceedings before the Office, such as opposition, re-examination or other administrative revocation procedures as well as to proceedings before any other competent authority, including a court.  It also applies to all such proceedings irrespective of the grounds for revocation or invalidation, that is including substantive grounds, for example, lack of novelty. However, except as provided under PLT Article 10(1), the grounds on which a granted patent may be revoked or invalidated, such as lack of novelty, as well as any other aspect of such proceedings, are not regulated by Article 10(2) and remain a matter for the applicable law of the PLT Contracting Party concerned. 

Further, PLT Article 11 provides the extension of a time limit for an applicant’s action before the patent office under certain conditions, and PLT Article 12 requires Contracting Parties to provide reinstatement of rights where an applicant lost his rights because of the failure to observe a time limit, if the failure occurred in spite of due care required by the circumstances or was unintentional.  However, in accordance with PLT Rules 12(5)(vi) and 13(iv), no Contracting parties shall be required to grant a relief under PLT Article 11 or reinstatement of rights under Article 12 in respect of a time limit for an action in inter partes proceedings.  In other words, a Contracting party is free to provide, or not to provide, the extension of a time limit and/or the reinstatement of rights regarding a time limit for an action in inter partes opposition, inter partes re-examination or other inter partes administrative revocation proceedings.

However, when adopting these Rules, the Diplomatic Conference adopted Agreed Statement No. 5, stating that while it was appropriate to exclude actions in relation to inter partes proceedings from the relief provided by Articles 11 and 12, it was desirable that the applicable laws of the Contracting Parties provide appropriate relief in those circumstances which takes into account the competing interests of third parties, as well as the interests of others who are not parties to the proceedings.

  • Summary table PDF, Revocation Mechanisms summary table
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