What is the difference between pre-grant and post-grant opposition to a patent

Question

A competitor has filed a patent application that I believe is invalid, and I want to know how to oppose it in India. I have been reading conflicting things online and I would like to understand what Indian law actually says about this, which Act and Section applies, what the realistic timelines and costs are, and what I should be doing right now to protect my position. If the matter can be resolved without litigation I would prefer that route, but I want to know what my rights are before I agree to anything or sign any document.

MyVakeel Legal Desk · Accepted Answer

What is the difference between pre-grant and post-grant opposition to a patent is governed in India primarily by Patents Act, 1970, Section 25(1) and Patents Act, 1970, Section 25(2). The short answer is set out below, followed by the practical steps most people in this situation need to take. Read it alongside the specific provisions named, because the exact relief available to you turns on the facts you can prove on paper.

Section 25(1) of the Patents Act, 1970 allows any person to file a pre-grant opposition (also called a representation) at any time after publication of the application but before grant of the patent, on statutory grounds including lack of novelty, obviousness, insufficient disclosure, wrongful obtaining, and non-patentability under Section 3, without requiring the opponent to pay a fee or prove standing as a 'person interested'.

Section 25(2) allows only a 'person interested', typically a competitor or someone in the same trade, to file a post-grant opposition within twelve months from the date of publication of grant of the patent, on largely the same statutory grounds, and this is heard by an Opposition Board of three examiners who submit a recommendation to the Controller.

Pre-grant opposition is decided by the Controller directly after considering the representation and the applicant's response, without a mandatory Opposition Board, whereas post-grant opposition follows a more elaborate procedure involving pleadings, evidence and a hearing before the Controller, based on the Opposition Board's joint recommendation.

Beyond opposition, any person interested or the Central Government can also file a revocation petition before the High Court (post the abolition of the IPAB) under Section 64 at any time after grant, on grounds overlapping with those available in opposition, making the patent's validity challengeable throughout its twenty-year term.

What to do next: 1) Identify whether the application is still pending (pre-grant) or already granted (post-grant); 2) Gather prior art and technical evidence showing lack of novelty or inventive step; 3) File the representation or opposition within the applicable statutory window; 4) Engage a patent agent to draft technical arguments and evidence affidavits.

If the other side has already issued a notice, filed a case or set a deadline, treat the matter as time-sensitive — most remedies under Patents Act, 1970, Section 25(1) carry limitation periods, and a delay you cannot explain weakens an otherwise strong case. You can post the details on the MyVakeel forum for a practising advocate to review, or book a paid consultation with a Bar Council verified lawyer in this practice area.