Patent Opposition

Patent opposition in India exists in two forms: pre-grant opposition (filed after the patent application is published at 18 months but before the patent is granted) and post-grant opposition (filed within one year of the patent grant date). Pre-grant opposition can be filed by any person under Section 25(1) of the Patents Act, 1970, and does not require the opponent to be personally affected. Post-grant opposition, under Section 25(2), also allows any person to oppose, but must be filed within the strict one-year window. The grounds for patent opposition are comprehensive and include: the invention is not patentable (lack of novelty, obviousness, or industrial application), the invention falls within the exclusions of Section 3, the patent was obtained wrongfully (the inventor is not the true and first inventor), the complete specification does not sufficiently describe the invention, the claims are broader than what is actually invented, the applicant failed to disclose information about foreign applications (a common ground based on Section 8 non-compliance), and the patent is contrary to natural justice or public interest. Patent opposition is one of the most technically demanding areas of IP law. The opponent must demonstrate, with specific prior art evidence, that the claimed invention does not meet the patentability criteria. This requires both deep technical knowledge (to understand the invention and the prior art) and legal expertise (to present the argument effectively within the procedural framework). Our team of patent attorneys and technical experts handles both sides — filing pre-grant and post-grant oppositions to block invalid patents, and defending our clients’ patents against third-party oppositions.

For Pre-grant opposition (Section 25(1)), any person can file a challenge. For Post-grant opposition (Section 25(2)), only a "person interested" (competitor, trade association, or researcher) can file within 12 months of patent grant.