Revocation of Patents Under Section 64 of Patents Act, 1970

A patent, once granted, is not inviolable. The Patents Act, 1970 recognizes that the grant of a patent is an administrative act performed on the basis of an examination that, however thorough, may not always capture every deficiency in an application whether a failure of novelty, an insufficient disclosure, a statutory exclusion that was not identified or a misrepresentation that induced the grant. The law therefore provides a mechanism by which a granted patent may be challenged and, where the challenge succeeds, revoked. That mechanism is principally housed in Section 64 of the Patents Act, 1970, which sets out the grounds on which a patent may be revoked and the procedure by which revocation may be sought. Section 64 is one of the most consequential provisions in Indian patent law it is the instrument through which competitors, public interest litigants and the government itself may challenge the validity of a patent that ought never to have been granted and it is invoked with significant frequency in contested pharmaceutical, technology and industrial patent matters.

Understanding Section 64 requires an appreciation of both its substantive content the grounds on which revocation may be sought and its procedural architecture the forums in which it may be invoked, the parties who may invoke it and the procedural steps that govern the conduct of revocation proceedings. It also requires an understanding of the relationship between Section 64 and other provisions of the Act that bear on patent validity, including Section 25 which governs pre-grant and post-grant oppositions and Section 66 which empowers the Central Government to revoke a patent in the public interest. Together, these provisions constitute the invalidation framework of Indian patent law a framework whose design reflects India’s characteristic insistence that patent monopolies be earned, maintained and exercised in accordance with both the letter and the spirit of the law.

The Nature and Purpose of Revocation

Revocation is the formal cancellation of a granted patent, with the effect that the patent is treated as having never been granted or, more precisely, that the patentee’s exclusive rights are extinguished from the date of revocation. It is a remedy of considerable gravity and the law treats it accordingly, requiring that the party seeking revocation establish the relevant ground or grounds on the balance of probabilities and providing the patentee with a full opportunity to be heard and to amend the patent in appropriate cases before revocation is ordered.

The policy rationale for revocation is rooted in the fundamental bargain that underlies the patent system. Society grants a patent holder a time-limited monopoly over an invention in exchange for a full and enabling disclosure of that invention to the public. Where that bargain has been breached because the invention was not truly new or was obvious or was not properly disclosed or was not even an invention at all under the statutory definition the patent should not stand. Revocation corrects the error of grant, restores the invalidly patented subject matter to the public domain and protects competitors, consumers and the public from the chilling effects of a monopoly that was never legitimately earned.

Who May File for Revocation – Locus Standi

Section 64(1) of the Patents Act provides that a patent may be revoked on a petition of any person interested or of the Central Government or on a counter-claim in a suit for infringement of the patent. The phrase “any person interested” has been interpreted broadly by Indian courts. It encompasses not only direct competitors who are affected by the patent in their commercial activities but also public interest organizations, generic pharmaceutical manufacturers, research institutions and indeed any person who can demonstrate a genuine interest in the subject matter of the patent or its impact. The breadth of locus standi under Section 64 reflects the legislative recognition that the validity of a patent is a matter of public concern, not merely a private dispute between the patentee and a specific competitor.

The Central Government’s power to petition for revocation is an expression of the state’s interest in ensuring that the patent system operates in the public interest and that patents are not used as instruments of anti-competitive conduct or as barriers to essential public goods. The counter-claim route by which a defendant in an infringement suit may raise revocation as a defence and as an affirmative claim is among the most frequently used in practice, since parties facing infringement allegations have both a legal incentive and a commercial motivation to challenge the validity of the patent being asserted against them.

The Forums for Revocation

Prior to the abolition of the Intellectual Property Appellate Board by the Tribunals Reforms Act, 2021, revocation petitions under Section 64 were filed before the IPAB. Following the IPAB’s abolition, its jurisdiction over revocation petitions has been transferred to the High Courts. Revocation petitions filed as independent proceedings are now heard by the High Court having jurisdiction, while counter-claims in infringement suits are heard by the court before which the infringement suit is pending which in practice means the High Courts, since original jurisdiction in patent infringement matters vests in the High Courts under Section 104 of the Patents Act.

This jurisdictional landscape has significant practical implications. Revocation proceedings before the High Courts are conducted according to the Code of Civil Procedure, 1908 and the rules of the relevant High Court, which means they are subject to the procedural rigours and potential delays of civil litigation. The evidentiary standards, the scope for discovery, the ability to lead expert evidence and the procedural framework for hearings are all governed by civil court procedure rather than the more streamlined administrative process that characterized IPAB proceedings. This shift has made revocation proceedings more complex and potentially more expensive, but it has also placed patent validity determinations in the hands of courts with constitutional status and established appellate hierarchies.

The Grounds of Revocation Under Section 64(1)

Section 64(1) sets out a comprehensive catalogue of grounds on which revocation may be sought. Each ground is independent a petitioner need establish only one ground to succeed, though in practice revocation petitions typically plead multiple grounds in the alternative. The grounds collectively address every significant deficiency that can afflict a granted patent, from failures of patentability to failures of disclosure to fraud upon the Patent Office.

Section 64(1)(a) – Wrongful Obtaining

The first ground is that the patent was granted to a person not entitled to apply for it specifically, that the patentee is not the true and first inventor and did not derive title from the true and first inventor through assignment or operation of law. This ground addresses the situation where a patent has been obtained by a person who wrongfully claimed the invention as their own, either by appropriating the invention of another or by filing without obtaining the necessary title. It is related to the pre-grant and post-grant opposition ground under Section 25 and to the right of a true inventor to seek a declaration of entitlement under Section 52 of the Act.

Section 64(1)(b) – Prior Grant in India

A patent may be revoked if the invention has been claimed in a valid claim of earlier priority date contained in another patent granted in India. This ground prevents the simultaneous existence of two valid Indian patents covering the same invention, a situation that would create confusion about the identity of the true patent holder and could result in double monopoly over the same subject matter. The earlier-priority patent prevails and the later-granted patent is revocable on this ground.

Section 64(1)(c) – Prior Publication

The patent is revocable if the invention, so far as claimed in any claim of the complete specification, was publicly known or publicly used in India before the priority date of that claim. This ground is an expression of the novelty requirement – a patent should not subsist over subject matter that was already in the public domain in India before the date of the patent. “Publicly known” and “publicly used” are interpreted to encompass any disclosure that made the invention available to the public, whether through publication, commercial use, demonstration or any other means by which the information could have been accessed by a member of the public.

Section 64(1)(d) – Prior Publication Outside India

This ground extends the prior publication basis to publications outside India. If the invention was published outside India before the priority date of the relevant claim – in a scientific paper, a patent specification, a conference proceeding, a product manual or any other published document – the claim is not novel and the patent is revocable on this ground. The availability of global patent databases and scientific literature repositories has made the identification of foreign prior art significantly more accessible than it was at the time the Patents Act was originally drafted and this ground is among the most commonly established in revocation proceedings.

Section 64(1)(e) – Obviousness and Lack of Inventive Step

A patent may be revoked if the invention is obvious and does not involve any inventive step, having regard to what was known or used before the priority date of the claim. This ground directly operationalize the inventive step requirement of Section 2(1)(ja), which defines an invention with an inventive step as one involving a feature that makes it not obvious to a person skilled in the art. The assessment of obviousness in revocation proceedings, as in examination, requires the court to adopt the perspective of a person skilled in the relevant art at the priority date, armed with the common general knowledge in that field and to assess whether the claimed invention would have been obvious to that person in light of the prior art.

Obviousness arguments in revocation proceedings are typically supported by expert evidence – testimony from technically qualified experts who opine on the state of the art at the priority date and on whether the claimed advance would have been within the reach of a skilled person exercising routine skill and knowledge. The quality and credibility of expert evidence is often determinative in contested obviousness cases and the selection and preparation of experts is a critical aspect of revocation litigation strategy.

Section 64(1)(f) – Not an Invention Under the Act

A patent may be revoked if the subject matter of any claim is not an invention within the meaning of the Act. This ground encompasses the Section 3 exclusions – if the patented subject matter falls within any of the categories listed in Section 3, it is not an invention for the purposes of the Act and the patent should not have been granted. This ground is frequently invoked in pharmaceutical revocation proceedings, where Section 3(d) is the most commonly pleaded basis and in technology revocation proceedings, where Section 3(k) is invoked against software and computer-implemented invention patents. It is, in effect, a post-grant enforcement of the same exclusions that examiners apply during prosecution.

Section 64(1)(g) – Insufficiency of Description

The patent is revocable if the complete specification does not sufficiently and fairly describe the invention and the method by which it is to be performed that is, if it is not fully and particularly described or if the best method of performing the invention known to the applicant at the date of filing is not disclosed. This ground enforces the fundamental quid pro quo of the patent bargain: the patentee receives exclusivity in exchange for a full and enabling disclosure. A specification that does not enable a person skilled in the art to reproduce the invention or that withholds the best mode known to the applicant, has not fulfilled this obligation and the patent should not stand.

Insufficiency is assessed from the perspective of a person skilled in the art reading the specification at the priority date. The question is whether such a person, using the specification together with the common general knowledge in the field, could perform the invention across its full claimed scope without undue experimentation. Where the claims are broad but the disclosure is narrow a recurring issue in biotechnology, pharmaceutical and chemical patents where applicants seek wide claims over functional classes of compounds insufficiency is a potent ground for revocation.

Section 64(1)(h) – Failure to Disclose Information

A patent may be revoked if the applicant has failed to disclose to the Controller information required under Section 8 of the Patents Act. Section 8 imposes a duty on applicants for Indian patents to disclose information regarding corresponding patent applications filed in other countries the status of those applications, the claims allowed and any prior art cited against them. This duty is a continuing one throughout the prosecution of the Indian application. The rationale is that information generated in foreign prosecution including prior art cited by foreign examiners and claim amendments made to overcome that art is directly relevant to the examination of the Indian application and its suppression deprives the Patent Office of material that might bear on the grant decision.

Revocation on this ground requires not merely that the applicant failed to disclose but that the failure was material that the information withheld was of a kind that could have affected the outcome of examination. In practice, this ground is often pleaded in conjunction with other substantive grounds, since the foreign prosecution history may reveal prior art or admissions against interest that independently support revocation on novelty or inventive step grounds.

Section 64(1)(i) Patent Obtained by Fraud

A patent may be revoked if it was obtained in consequence of the failure to disclose or the furnishing of false information to the Controller. This is the most serious ground of revocation, involving an element of dishonest conduct by the applicant. It captures not only active misrepresentation the provision of false data or false statements but also suppression of material information that was known to the applicant and whose disclosure might have led to a different outcome in examination. Fraud upon the Patent Office is treated with particular severity and a patent obtained through fraud has no equity in its favour.

Section 64(1)(j) – Geographical Indications

A patent may be revoked if the primary or intended use or commercial exploitation of the invention is contrary to law or morality or is seriously prejudicial to human, animal or plant life or health or to the environment. This ground substantially overlaps with the Section 3(b) exclusion and serves as its post-grant counterpart it ensures that patents that should have been refused on public order or morality grounds do not escape challenge simply because the examination process failed to identify them.

Section 64(1)(k) Scope of Claims Beyond Disclosure

The patent is revocable if the scope of any claim of the complete specification is not sufficiently and clearly defined or that any claim of the complete specification is not fairly based on the matter disclosed in the specification. This ground addresses the situation where the claims, in their final form, extend beyond what is disclosed and enabled in the specification a form of claim overreaching that is contrary to the principle that the patentee’s monopoly must be commensurate with their technical contribution. Where claims have been broadened during prosecution to capture subject matter not described in the specification or where the specification’s disclosure is insufficient to support the breadth of the claims, this ground provides a basis for revocation or for the partial revocation of the offending claims.

Partial Revocation – Section 64(2)

Section 64(2) provides that where a ground of revocation has been established but it relates only to some of the claims or some part of a claim in the complete specification, the court may revoke only those claims or that part of a claim to which the ground relates, leaving the remaining valid claims intact. This provision reflects the principle of severability in patent law the recognition that a single patent document may contain some claims that are valid and others that are not and that the invalidity of some claims does not necessarily infect the entire patent.

Partial revocation is an important tool in revocation litigation strategy. A petitioner who cannot establish grounds against all claims may nonetheless succeed in removing the broadest and most commercially significant claims, leaving the patentee with narrower claims of reduced commercial value. Conversely, a patentee facing a revocation petition should identify, at an early stage, which claims are most vulnerable and which are most defensible and should be prepared to argue for partial revocation as a fallback position if the stronger claims cannot be maintained.

The Relationship Between Section 64 and Section 25 Opposition and Revocation

Section 25 of the Patents Act provides for opposition to patents both pre-grant under Section 25(1) and post-grant under Section 25(2). Post-grant opposition under Section 25(2) must be filed within twelve months of the date of publication of the grant of the patent and it is heard by an Opposition Board constituted by the Controller. The grounds available in post-grant opposition substantially overlap with the grounds available in revocation proceedings under Section 64 and a party that has unsuccessfully opposed a patent under Section 25(2) may subsequently seek revocation under Section 64, though the previous opposition outcome will be a relevant consideration.

The existence of parallel routes opposition before the Patent Office and revocation before the High Court is a distinctive feature of Indian patent law. In practice, the choice between them is driven by considerations of timing, cost, forum and strategic objective. Post-grant opposition under Section 25(2) is faster and less expensive than High Court revocation proceedings, but the High Court offers greater procedural scope for discovery and expert evidence and its orders carry the authority of judicial precedent. Counter-claim revocation in an infringement suit is often the most powerful avenue, since it places the patent’s validity squarely in issue in the same proceedings in which it is being enforced.

The Revocation of Patents in the Public Interest – Section 66

Section 66 of the Patents Act confers on the Central Government an independent power to revoke a patent in the public interest where it is satisfied that a patent or the manner in which it is exercised is mischievous to the State or generally prejudicial to the public. This is a broader and more policy-oriented power than the grounds-based revocation under Section 64. It does not require the government to establish any of the specific grounds listed in Section 64 it requires only that the patent or its exercise is contrary to the public interest. The government must give the patentee an opportunity to be heard before exercising this power and the exercise of the power is subject to judicial review.

Section 66 has been invoked relatively rarely, but its existence functions as an important background guarantee a reminder that in the Indian legal framework, patent rights are held subject to the overriding interest of the public and the state.

Landmark Cases in Patent Revocation

The revocation jurisprudence of Indian courts has been shaped by a series of significant decisions that have defined the application of the Section 64 grounds and the procedural standards governing revocation proceedings.

In Novartis AG v. Union of India, (2013) 6 SCC 1, the Supreme Court’s holding on Section 3(d) effectively resolved the question of patentability that had been at the heart of opposition proceedings, reinforcing the principle that the Section 3 exclusions operate as absolute bars that cannot be overcome by routine pharmaceutical innovation involving new forms of known substances without enhanced therapeutic efficacy.

In Bayer Corporation v. Union of India & Ors., revocation and compulsory licensing considerations intersected, with the court’s analysis of working requirements and public access directly informing the landscape in which revocation petitions involving pharmaceutical patents are assessed.

In Roche v. Cipla, the Delhi High Court’s assessment of patent validity in the context of an infringement suit where Cipla raised invalidity as a defence demonstrated the manner in which revocation arguments are integrated into infringement proceedings and the weight given to public interest considerations in determining both validity and relief.

In Enercon (India) Ltd. v. Aloys Wobben, the Delhi High Court engaged extensively with the procedural framework for revocation proceedings, including questions of burden of proof, the scope of permissible evidence and the relationship between the revocation jurisdiction of the court and the examination function of the Patent Office. The case, which concerned wind turbine technology patents, produced detailed analysis of the prior publication and obviousness grounds under Section 64.

Conclusion

Section 64 of the Patents Act, 1970 is the law’s most important guarantee against the entrenchment of invalid patents. It ensures that the patent system remains self-correcting that errors in grant can be identified and remedied, that competitors are not permanently foreclosed by patents that should never have been issued and that the public domain is protected from encroachment by monopolies that were not legitimately earned. The grounds it provides are comprehensive, the locus standi it confers is broad and the forums in which it operates the High Courts and through counter-claim in infringement proceedings are well equipped to deliver substantive justice in complex technical cases.

For those challenging patents, Section 64 demands rigorous preparation: prior art searches of the highest quality, careful analysis of the specification for insufficiency, expert evidence on obviousness and a strategic assessment of which grounds offer the strongest prospect of success. For patentees defending their patents, Section 64 demands equally rigorous preparation in the other direction: a clear understanding of each ground pleaded against them, a well-organized evidentiary response, a readiness to amend claims in appropriate cases and an ability to present the technical merits of the invention clearly and compellingly to a judicial audience. In both respects, Section 64 revocation proceedings are among the most intellectually demanding engagements in Indian intellectual property practice.

References

The Patents Act, 1970 – https://ipindia.gov.in
The Patents Rules, 2003 – https://ipindia.gov.in
Manual of Patent Office Practice and Procedure – https://ipindia.gov.in
Novartis AG v. Union of India, (2013) 6 SCC 1 – https://main.sci.gov.in
Bayer Corporation v. Union of India & Ors. – https://ipindia.gov.in
Enercon (India) Ltd. v. Aloys Wobben, Delhi High Court – https://delhihighcourt.nic.in
F. Hoffmann-La Roche Ltd. v. Cipla Ltd., (2012) 49 PTC 356 (Del) – https://delhihighcourt.nic.in
Tribunals Reforms Act, 2021 – https://legislative.gov.in
TRIPS Agreement, WTO –https://www.wto.org/english/docs_e/legal_e/27-trips.pdf
National IPR Policy, 2016, DPIIT – https://dpiit.gov.in

Revocation of Patents under Section 64 – Grounds and Procedure

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