Protecting innovation isn’t just about filing patents—it’s about knowing what happens after you file. Every great idea faces scrutiny before it earns the right to exclusivity, and in India, that scrutiny takes shape through the patent opposition system.
Whether you’re an inventor trying to secure your first patent, a startup founder defending your edge, or simply curious about how ideas are tested before they’re truly protected, understanding this process is essential.
Because in the world of patents, a grant isn’t the finish line—it’s the beginning of the real test.
1. The Rationale Behind Patent Opposition
The opposition system acts as a public safeguard against wrongful or unjust patent grants.
It ensures that inventions granted monopoly rights truly meet the legal standards of novelty, inventive step, and industrial applicability under Sections 2(1)(j), 2(1) (ja), and 2(1)(ac) respectively of the Indian Patent Act, 1970.
It also allows the public, including competitors, researchers, and industry stakeholders, to contribute to patent examination by highlighting prior art or deficiencies that might have been overlooked.
2. Pre-Grant Opposition – Section 25(1)
When Can It Be Filed?
A pre-grant opposition can be filed any time after the publication of the patent application under Section 11A, but before the patent is granted.
This means once the patent is published (usually after 18 months from filing), the public gets the right to challenge it before it proceeds to grant.
Who Can File It?
Interestingly, any person can file a pre-grant opposition, not just a person skilled in the art.
This broad standing under Section 25(1) allows public participation and transparency in the grant process.
The phrase “any person” includes individuals, organisations, competitors, or even NGOs concerned about the public impact of a particular technology.
3. Grounds for Pre-Grant Opposition
The grounds for opposition under Section 25(1) are similar to those under Section 25(2) (post-grant opposition). They include the following:
- Wrongful obtainment – The invention was wrongfully obtained from the opponent.
- Prior publication – The invention was published before the priority date.
- Prior claim – The invention was already claimed in an earlier patent.
- Prior public knowledge or use – The invention was publicly known or used in India.
- Obviousness or lack of inventive step.
- Non-patentable subject matter – The invention falls under non-patentable categories (e.g., Section 3 or Section 4 of the Indian Patent Act, 1970).
- Insufficient disclosure – The complete specification doesn’t sufficiently describe the invention or best mode.
- Failure to disclose information under Section 8 (Information about corresponding foreign patent applications filed for the same invention).
- Convention application not filed within the prescribed time.
- Wrong mention of biological source or geographical origin.
- Invention anticipated by traditional knowledge.
These broad grounds ensure that both legal and technical deficiencies can be examined before a patent monopoly is granted.
4. Procedure for Pre-Grant Opposition (Rule 55)
A representation for pre-grant opposition under Section 25(1) must be filed in Form 7A at the appropriate patent office, with a copy to the applicant. It should include a statement, supporting evidence (if any), and a request for a hearing, if desired. The Controller will consider such a representation only after a request for examination has been filed, and no patent shall be granted before six months from the publication date under Section 11A. If no prima facie case is found, the Controller notifies the opponent and may refuse the representation unless a hearing is requested. If a prima facie case is made out, the applicant is notified and may file a reply with evidence within two months. After considering all submissions, evidence, and hearings, the Controller may reject the representation, require amendments to the specification, or refuse the patent by passing a reasoned (speaking) order. A post-grant opposition under Section 25(2) must be filed in Form 7 in duplicate at the appropriate office, as provided under Rule 55A.
5. Post-Grant Opposition – Section 25(2)
When Can It Be Filed?
A post-grant opposition can be filed within one year from the date of publication of the grant of a patent under Section 43(2).
This allows interested parties to challenge a granted patent after it enters into force but before it matures into an unassailable right.
Who Can File It?
Unlike pre-grant opposition, post-grant opposition can be filed only by “any person interested”, meaning someone with a commercial, research, or legal interest in the same subject matter.
This ensures that only genuinely affected entities challenge granted patents.
6. Constitution of the Opposition Board – Rule 56
Upon receiving a notice of post-grant opposition under Rule 55A, the Controller constitutes an Opposition Board comprising three members, one of whom is nominated as the Chairman. Any examiner appointed under Section 73(2) may serve as a member, except the examiner who was previously involved in the examination or grant proceedings of the concerned patent application. The Opposition Board examines the notice of opposition, and all related documents filed under Rules 57 to 62, evaluates each ground of opposition, and submits a joint report with reasons and recommendations to the Controller within two months from the date the documents were forwarded to it.
7. Procedure for Post-Grant Opposition (Rules 57–62)
In a post-grant opposition, the opponent must file a written statement and supporting evidence in duplicate along with the notice of opposition, clearly stating their interest, grounds, and relief sought, and must also share a copy with the patentee. The patentee, if wishing to contest, must file a reply statement and evidence within two months of receiving the opponent’s documents, with a copy to the opponent; otherwise, the patent is deemed revoked. The opponent may then file reply evidence within one month, limited to issues raised by the patentee’s evidence. No additional evidence may be submitted by either party unless permitted by the Controller before the hearing is fixed.
Both parties must provide authenticated copies of all documents referred to, in duplicate, and supply English translations if any material is in another language. Once evidence submission is complete and the Opposition Board’s report is received, the Controller schedules a hearing, giving at least ten days’ notice to the parties, who must confirm attendance with the prescribed fee. If either party wishes to rely on any new publication during the hearing, at least five days’ prior notice must be given. After hearing the parties and considering the Board’s recommendations, the Controller issues a reasoned decision and notifies both sides.
8. Strategic Implications
For applicants, the pre-grant opposition serves as both a challenge and an opportunity. While it may delay the grant and expose potential weaknesses, it also ensures a more robust patent once granted. For competitors and the public, it acts as an early filter to prevent undeserving patents from entering the system. In contrast, post-grant opposition functions as a powerful, cost-effective alternative to full-scale litigation, allowing interested parties to contest questionable patents before resorting to revocation proceedings under Section 64 of the Patents Act.
9. A System of Balance
India’s two-tier opposition framework strikes a thoughtful balance between protecting innovation and safeguarding public interest. The pre-grant opposition promotes transparency and quality by inviting public scrutiny before exclusivity is granted, while the post-grant opposition offers a formal legal avenue to challenge patents after grant, ensuring continued accountability. Together, they underscore a fundamental truth of patent law that granting a patent is not the end of examination, but a checkpoint in the ongoing journey of innovation and integrity.
Because innovation that withstands opposition doesn’t just survive, it leads the future.
At R K Dewan & Co., innovation meets precision. As a leading patent law firm in India, we combine over seven decades of legal expertise with technical depth to help inventors, startups, and global enterprises protect and maximize the value of their ideas. Our team of 175+ IP professionals works across Mumbai, New Delhi, Pune, Chennai, Kolkata, Bangalore, and Indore—offering end-to-end patent services from drafting and filing to prosecution, opposition, and litigation. Whether it’s navigating India’s patent opposition system, conducting prior art searches, or managing large IP portfolios, RKD provides practical, timely, and strategic counsel designed to strengthen your competitive edge and secure innovation that lasts.
