Re-examination Systems

A re-examination is a proceeding conducted by the patent office after the grant of a patent in which the validity of a patent is re-examined at the request of the patentee or third party, as provided by the applicable law.

In some countries, a re-examination system is provided as an alternative or complement to the opposition system.  In comparison to the opposition system, in general, the re‑examination is not time-bound and can be requested during the lifetime of the patent.  In some countries the re-examination is conducted by a single examiner or the division of the patent office which has granted the patent in the first place, in comparison to a full opposition board in the cases of post-grant oppositions.

The re-examination procedures are conducted ex parte in some countries (largely without the participation of the requester in the conduct of the re-examination) and inter partes in some other countries (with greater participation of the requester in the re-examination process).  The ex parte re-examination is often characterized as a system that provides for quality check through a second patent examination of the patent by the patent office. 

The inter partes re‑examination in certain countries may resemble to administrative revocation or invalidation mechanisms in some other countries in the sense that both provide for a wide range of substantive grounds and inter partes proceedings which allow third parties to challenge a patent before an administrative body.  However, the proceedings of the inter partes re-examination are generally more conducted as a second examination by the patent office itself than as a full inter partes administrative review by a specialized board. 

In general, the re‑examination may be requested mainly on the basis of documentary evidence, and an opportunity to appeal against the re‑examination decision is generally possible. 

The re-examination system often has an estoppel effect, as the requester of re-examination is, in most countries, estopped from basing judicial review on the same grounds as the re-examination. 

Depending on the expected role of the re-examination system in the entire review mechanisms placed in the national patent system, procedural as well as substantive requirements regarding the re-examination are different from one country to another. 

In general, the re-examination procedures vary with respect to: 

  • entitlement to request re‑examination; 
  • ex parte or inter partes nature of re-examination; 
  • the disclosure of identity of requester; 
  • the grounds of re-examination;  and
  • the re‑examination fee.

In some countries, procedures exist to provide the opportunity for third parties or the patentee to request a re-examination of the granted patent. The primary objective of the re examination is similar to other revocation proceedings conducted at the administrative level by the patent office, such as post-grant opposition or invalidation, in the sense that it provides a relatively quick and inexpensive alternative to litigation to reconsider the validity of an issued patent. In general, it allows the re examination of a patent in view of new prior art or on other grounds, as provided in the applicable law, and to correct a patent which was inadvertently issued.

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:  (i) form or contents of application (PLT Article 6(1));  (ii) formal requirements relating to request form, fees and priority document (PLT Article 6(2), (4) and (5));  (iii) form and means of transmittal of communications (PLT Article 8(1) and (3));  and (iv) 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
  • Australia PDF, National laws - Australia
  • Canada PDF, National laws - Canada
  • Denmark PDF, National laws - Denmark
  • Dominican Republic PDF, National laws - Dominican Republic
  • New Zealand PDF, National laws - New Zealand
  • Norway PDF, National laws - Norway
  • Republic of Korea PDF, National laws - Republic of Korea
  • Republic of Moldova PDF, National laws - Republic of Moldova
  • Singapore PDF, National laws - Singapore
  • United States of America PDF, National laws - United States of America