Opposition to patent
Section 25 of the Patents Act, 1970 deals with opposition to patent. 1,[25. Opposition to the patent.-- (1) Where an application for a patent has been published but a patent has not been granted, any person may, in writing, represent by way of opposition to the Controller against the grant of patent on the ground-- (a) that the applicant for the patent or the person The Act came into force on 01 Apr 1978.
1,2[25. Opposition to the patent.-- (1) Where an application for a patent has been published but a patent has not been granted, any person may, in writing, represent by way of opposition to the Controller against the grant of patent on the ground--
(a) that the applicant for the patent or the person under or through whom he claims, wrongfully obtained the invention or any part thereof from him or from a person under or through whom he claims;
(b) that the invention so far as claimed in any claim of the complete specification has been published before the priority date of the claim--
(i) in any specification filed in pursuance of an application for a patent made in India on or after the 1st day of January, 1912; or
(ii) in India or elsewhere, in any other document:
Provided that the ground specified in sub-clause (ii) shall not be available where such publication does not constitute an anticipation of the invention by virtue of sub-section (2) or subsection (3) of section 29;
(c) that the invention so far as claimed in any claim of the complete specification is claimed in a claim of a complete specification published on or after the priority date of the applicant's claim and filed in pursuance of an application for a patent in India, being a claim of which the priority date is earlier than that of the applicants claim;
(d) that 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.
Explanation.--For the purposes of this clause, an invention relating to a process for which a patent is claimed shall be deemed to have been publicly known or publicly used in India before the priority date of the claim if a product made by that process had already been imported into India before that date except where such importation has been for the purpose of reasonable trial or experiment only;
(e) that the invention so far as claimed in any claim of the complete specification is obvious and clearly does not involve any inventive step, having regard to the matter published as mentioned in clause (b) or having regard to what was used in India before the priority date of the applicant's claim;
(f) that the subject of any claim of the complete specification is not an invention within the meaning of this Act, or is not patentable under this Act;
(g) that the complete specification does not sufficiently and clearly describe the invention or the method by which it is to be performed;
(h) that the applicant has failed to disclose to the Controller the information required by section 8 or has furnished the information which in any material particular was false to his knowledge;
(i) that in the case of a convention application, the application was not made within twelve months from the date of the first application for protection for the invention made in a convention country by the applicant or a person from whom he derives title;
(j) that the complete specification does not disclose or wrongly mentions the source or geographical origin of biological material used for the invention;
(k) that the invention so far as claimed in any claim of the complete specification is anticipated having regard to the knowledge, oral or otherwise, available within any local or indigenous community in India or elsewhere,
but on no other ground and the Controller shall, if requested by such person for being heard, hear him and dispose of such representation in such manner and within such period as may be prescribed.
(2) At any time after the grant of patent but before the expiry of a period of one year from the date of publication of grant of a patent, any person interested may give notice of opposition to the Controller in the prescribed manner on any of the following grounds, namely:--
(a) that the patentee or the person under or through whom he claims, wrongfully obtained the invention or any part thereof from him or from a person under or through whom he claims;
(b) that the invention so far as claimed in any claim of the complete specification has been published before the priority date of the claim--
(i) in any specification filed in pursuance of an application for a patent made in India on or after the 1st day of January, 1912; or
(ii) in India or elsewhere, in any other document:
Provided that the ground specified in sub-clause (ii) shall not be available where such publication does not constitute an anticipation of the invention by virtue of sub-section (2) or subsection (3) of section 29;
(c) that the invention so far as claimed in any claim of the complete specification is claimed in a claim of a complete specification published on or after the priority date of the claim of the patentee and filed in pursuance of an application for a patent in India, being a claim of which the priority date is earlier than that of the claim of the patentee;
(d) that 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.
Explanation.--For the purposes of this clause, an invention relating to a process for which a patent is granted shall be deemed to have been publicly known or publicly used in India before the priority date of the claim if a product made by that process had already been imported into India before that date except where such importation has been for the purpose of reasonable trial or experiment only;
(e) that the invention so far as claimed in any claim of the complete specification is obvious and clearly does not involve any inventive step, having regard to the matter published as mentioned in clause (b) or having regard to what was used in India before the priority date of the claim;
(f) that the subject of any claim of the complete specification is not an invention within the meaning of this Act, or is not patentable under this Act;
(g) that the complete specification does not sufficiently and clearly describe the invention or the method by which it is to be performed;
(h) that the patentee has failed to disclose to the Controller the information required by section 8 or has furnished the information which in any material particular was false to his knowledge;
(i) that in the case of a patent granted on convention application, the application for patent was not made within twelve months from the date of the first application for protection for the invention made in a convention country or in India by the patentee or a person from whom he derives title;
(j) that the complete specification does not disclose or wrongly mentions the source and geographical origin of biological material used for the invention;
(k) that the invention so far as claimed in any claim of the complete specification was anticipated having regard to the knowledge, oral or otherwise, available within any local or indigenous community in India or elsewhere,
but on no other ground.
(3) (a) Where any such notice of opposition is duly given under sub-section (2), the Controller shall notify the patentee.
(b) On receipt of such notice of opposition, the Controller shall, by order in writing, constitute a Board to be known as the Opposition Board consisting of such officers as he may determine and refer such notice of opposition along with the documents to that Board for examination and submission of its recommendations to the Controller.
(c) Every Opposition Board constituted under clause (b) shall conduct the examination in accordance with such procedure as may be prescribed.
(4) On receipt of the recommendation of the Opposition Board and after giving the patentee and the opponent an opportunity of being heard, the Controller shall order either to maintain or to amend or to revoke the patent.
(5) While passing an order under sub-section (4) in respect of the ground mentioned in clause (d) or clause (e) of sub-section (2), the Controller shall not take into account any personal document or secret trial or secret use.
(6) In case the Controller issues an order under sub-section (4) that the patent shall be maintained subject to amendment of the specification or any other document, the patent shall stand amended accordingly.]
Section 25, The Patents Act, 1970 (Act 39 of 1970).
Cross-references
Extracted from the operative text of the enactments themselves. Every destination below exists in our corpus.
This section refers to
Related judgements & precedents
These are some judgments that construed this section, and hold precedence value. They hold authority on how to read, interpret and use this section.
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Dr. Aloys Wobben v. Yogesh Mehra
Court's Decision & Legal Precedent
Judgment of Main Case order-26.pdf 2014-06-02. Index date 2014-06-02; body is the reportable Khehar J. CA 6718/2013 Dr. Aloys Wobben v. Yogesh Mehra (2014) 15 SCC 360. DATE-CHECK false-positive VERIFY (not DATE VERIFIED banner) — Ghisalal/Thwaha/Eera pattern; auto DATE-CHECK cites 2012-01-05 / 2006-09-29 / 2008-12-08 which are fact dates inside the named merits (assignment 05.01.2012; IP licence 29.9.2006; termination 8.12.2008). Isolate: Patents s.25 scheme — pre-grant opposition by “any person” (s.25(1)); post-grant opposition by “person interested” within 1 year (s.25(2)); s.25(2) proceedings eclipse s.64 revocation/counter-claim for the same person. Also election between IPAB s.64 petition and HC counter-claim. Map 25 and 64. Do not pad 48/84/107A. Twin order-27.pdf is the same file — use order-26.pdf.
On this section: Patents Act s.25(1) lets any person oppose before grant; s.25(2) confines post-grant opposition to a person interested within one year, and that proceeding eclipses a parallel s.64 revocation for the same person (Aloys Wobben).
The holding above is the ratio decidendi as extracted from the judgment by eCourts India, reproduced unaltered — it is a rendering of the court's reasoning, not a substitute for its words. Read the order itself before relying on it.
Judgments citing this section
These may be obiter dicta or a precedent, for you to study. These are the judgments where this section is quoted.
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… The relevant part of this judgment is set out below: "Distinction between pre-grant and post-grant opposition 13. In the first instance a distinction has to be drawn between a pre-grant opposition and a post-grant opposition. While a pre-grant opposition can be filed under Section 25 (1) of the Patents Act at any time after the publication of the patent application but before the grant of a patent, a post-grant opposition under Section 25(2) of the Patents Act has to be filed before the expiry of one year from the date of the publication of the grant of patent. A second significant difference, …
Made under this section, and citing it
4 instruments name this provision in its title or its text without being made under it.
Questions about Section 25
What have the courts held on Section 25 of the Patents Act?
Dr. Aloys Wobben v. Yogesh Mehra (02 Jun 2014) is the leading judgment on this section among those set out below: Patents Act s.25(1) lets any person oppose before grant; s.25(2) confines post-grant opposition to a person interested within one year, and that proceeding eclipses a parallel s.64 revocation for the same person (Aloys Wobben).
How do I find court cases under Section 25 of the Patents Act?
In judgments and charge sheets this section is written several ways, and each form finds a different set of orders. These search the full text of every order eCourtsIndia holds, best matches first: Patents Act 25, section 25 Patents Act, section 25 of the Patents Act. People searching for it also type uk patents act section 25. Each opens the full list of orders on eCourtsIndia, where it can be narrowed by court, year and outcome. 1 reported judgment on this section is set out on this page, beginning with Dr. Aloys Wobben v. Yogesh Mehra (02 Jun 2014).
What should I read with Section 25 of the Patents Act, and has it changed?
Its own text turns on section 8 (Information and undertaking regarding foreign applications), section 29 (Anticipation by previous publication), so none of them can safely be read on its own. 4 other provisions in this corpus refer back to it. 4 instruments name it without being made under it, most recently Patents (2nd Amendment) Rules, 2020 (2020), then The Patents (Amendment) Rules, 2016 (2016).
When did Section 25 of the Patents Act come into force?
Section 25 of the Patents Act, cited as Patents Act 25, came into force on 01 Apr 1978, having been enacted on 19 Sep 1970. It is in force as at the date shown on this page.
Other sections of this Act
Source and method. Compiled from the enactments of Parliament and of the State legislatures as published on India Code, and republished together with commentary and other original matter under section 52(1)(q)(ii) of the Copyright Act, 1957. Structured, cross-referenced and maintained by eCourtsIndia. Text as in force on 15 Oct 2026. This page is not a substitute for legal advice.