Two proceedings, different standing rules
Section 25 of the Patents Act, 1970 provides two opposition stages. Before grant, any person may make a representation against grant after the application is published and before the patent is granted. After grant, a person interested may give notice of opposition during the one-year period that begins on publication of the grant. The Act defines a person interested to include someone engaged in, or promoting, research in the same field as the invention; standing should be supported by the facts and record.
| Stage | Who may file | Window | Main form |
|---|---|---|---|
| Pre-grant | Any person | After publication and before grant | Form 7A |
| Post-grant | Any person interested | After grant publication and before expiry of one year from that publication | Form 7 |
The six-month period after application publication is a minimum no-grant period under Rule 55. It is not the filing deadline for an opponent: a pre-grant representation may be filed at any time before grant, subject to the statutory process. The Controller considers the representation only after a request for examination has been filed.
Pre-grant procedure
A pre-grant representation is filed in Form 7A with the grounds and supporting evidence, if any. If the Controller finds a prima facie case, notice is sent to the applicant. The applicant may file a statement and evidence within two months from that notice. The Controller considers the representation and examination record, and may hear the parties if requested. Rule 55 ordinarily calls for a speaking decision within one month after the proceedings are complete.
The current Rule 55 gives the applicant two months to file a statement and evidence after notice. A pre-grant opponent should keep the publication, examination and grant status under active review; the representation itself does not automatically suspend every prosecution step.
Post-grant procedure
A post-grant notice is made in Form 7. The opponent files a written statement explaining its interest, grounds and evidence. The patentee has two months from receiving the opponent's statement and evidence to file a reply and evidence. If the patentee does not contest within that period, Rule 58 says the patent is deemed revoked. The opponent may file reply evidence within one month, limited to matters in the patentee's evidence.
The Controller constitutes a three-member Opposition Board. Under Rule 56, it submits a reasoned report and recommendation within two months after receiving the relevant documents. The Board advises the Controller; the statutory decision remains with the Controller after the prescribed process and hearing. The written-statement, patentee-reply and opponent-reply stages are set out in Rules 57, 58 and 59.
Grounds and evidence
Section 25 contains defined grounds, including wrongful obtaining, prior publication or use, obviousness, excluded subject matter, insufficient disclosure, non-compliance with statutory filing requirements and failure to disclose required foreign-application information. The available grounds and evidence depend on the stage and the application record. Build a claim-by-claim chart, identify the relevant dates, and make the evidentiary basis clear.
The Delhi High Court's decision in Zydus Healthcare Ltd. v. Assistant Controller of Patents and Designs (24 December 2025) discusses the procedural separation between a pre-grant opposition and examination of the application. It is a procedural decision and should not be read as changing Section 25 standing or filing windows. The statutory text and current Rule 55, Rule 55A and Rules 56–59 remain the starting point.
This guide is general information, checked on 10 October 2026. Limitation, standing and evidence strategy require review of the particular patent and procedural record.