Pre-Grant vs Post-Grant Patent Opposition in India: Procedure, Grounds, Timelines, Fees and Strategic Considerations

Introduction

The Patents Act, 1970 provides multiple mechanisms for challenging the grant or validity of a patent in India. Two important statutory mechanisms are pre-grant opposition under Section 25(1) and post-grant opposition under Section 25(2). While both mechanisms allow third parties to challenge a patent on substantially similar grounds, they operate at different stages of the patent lifecycle and differ significantly in terms of standing, procedure, timelines, fees and strategic consequences.

A third mechanism is revocation of a patent under Section 64, which may be pursued by a person interested before the High Court or raised by way of a counterclaim in a patent infringement suit. The choice between pre-grant opposition, post-grant opposition and revocation proceedings can therefore have important implications for patent prosecution, commercial launch plans and subsequent patent litigation.

The Patents (Amendment) Rules, 2024 have further changed the pre-grant opposition procedure by introducing a prima facie screening mechanism, reducing certain timelines and introducing filing fees. Judicial decisions, including the Supreme Court’s decision in Dr. Aloys Wobben v. Yogesh Mehra, have also addressed the relationship between post-grant opposition, revocation proceedings and counterclaims.

This article examines the pre-grant and post-grant patent opposition procedure in India, including the grounds for opposition, filing requirements, applicable timelines and fees, and the interaction of opposition proceedings with patent revocation and infringement proceedings.

What is Pre-Grant Patent Opposition in India?

Under Section 25(1) of the Patents Act, 1970, any person may make a representation by way of opposition against the grant of a patent after the patent application has been published but before the patent is granted. A pre-grant opposition is filed in Form 7A under Rule 55 of the Patents Rules, 2003. The representation must contain the statement and evidence, if any, supporting the opposition and may include a request for a hearing.

Importantly, Rule 55(1A) provides that a patent cannot be granted before the expiry of six months from the date of publication of the application under Section 11A. However, a pre-grant opposition may be filed at any time before the actual grant of the patent. The broad standing requirement is one of the principal features of a pre-grant opposition: “any person” may file it. Unlike a post-grant opposition or a revocation petition under Section 64, the statute does not require the pre-grant opponent to establish that it is a “person interested”.

How to File a Pre-Grant Patent Opposition

A pre-grant opposition is filed with the Indian Patent Office in Form 7A, accompanied by the prescribed statement and evidence. Following the 2024 amendments, the Controller first considers whether the representation discloses a prima facie case.

If no prima facie case is made out, the Controller notifies the opponent. If the opponent does not request a hearing, the Controller may reject the representation by a reasoned order. If a hearing is requested, the opponent is given an opportunity to be heard before the Controller decides the representation. Where a prima facie case is made out, the Controller records reasons and notifies the applicant. The applicant may then file its statement and evidence within two months of the notice.

The Controller may ultimately reject the opposition, require amendments to the complete specification or other documents, or refuse the patent application, by a speaking order. The 2024 Rules also provide that where a representation for opposition has been filed and the requisite notice has been issued, the patent application is to be examined in accordance with the expedited examination framework under Rule 24C.

What is Post-Grant Patent Opposition in India?

A post-grant opposition under Section 25(2) can be filed after a patent has been granted, but only within one year from the date of publication of the grant of the patent.

Unlike a pre-grant opposition, a post-grant opposition may be filed only by a “person interested”. Section 2(1)(t) defines the expression inclusively and covers, among others, persons engaged in or promoting research in the same field as the invention and persons having specified manufacturing, trading or financial interests connected with the patented invention.

A post-grant opposition is filed in Form 7 under the Patents Rules, 2003. The opponent must set out the nature of its interest, the facts relied upon and the relief sought, together with the prescribed evidence.

Once a post-grant opposition is filed, the Controller notifies the patentee and constitutes an Opposition Board consisting of three members. The Board examines the opposition and submits a reasoned recommendation to the Controller. The Controller subsequently considers the Board’s recommendation and gives the patentee and opponent an opportunity of being heard before deciding whether the patent should be maintained, amended or revoked.

Grounds for Patent Opposition Under Section 25

The grounds for pre-grant and post-grant opposition are substantially similar. They include, among other grounds:

• wrongful obtaining of the invention;
• prior publication of the invention;
• prior claiming;
• prior public knowledge or public use in India;
• lack of novelty;
• obviousness or lack of inventive step;
• the invention not being patentable under the Patents Act;
• insufficient or inadequate disclosure of the invention;
• failure to disclose or furnishing of materially false information required under Section 8;
• wrongful or insufficient disclosure regarding the source or geographical origin of biological material; and
• anticipation of the invention by traditional or local knowledge.

Because the statutory grounds substantially overlap, the practical distinction between pre-grant opposition and post-grant opposition lies principally in their timing, standing requirements, procedure, cost and consequences.

Pre-Grant vs Post-Grant Patent Opposition: Key Differences

The applicable fees are subject to the First Schedule to the Patents Rules, 2003, as amended.

Pre-Grant Opposition After the Patents (Amendment) Rules, 2024

The Patents (Amendment) Rules, 2024, notified on 15 March 2024, introduced important changes to the pre-grant opposition process. The most significant change is the introduction of a preliminary prima facie assessment by the Controller. This means that a pre-grant representation is no longer automatically taken forward into the substantive opposition process. The Controller first considers whether the representation establishes a prima facie case.

The 2024 amendments also reduced the applicant’s response period from three months to two months. Further, where the Controller finds a prima facie case and issues the relevant notice, the application is examined under the expedited examination framework.

The amendments also introduced official fees for filing pre-grant oppositions. This replaced the earlier position under which no filing fee was payable for a pre-grant representation. These changes have made the procedure for filing a pre-grant patent opposition in India more structured and introduced an additional threshold intended to ensure that representations are substantively considered before the applicant is required to respond.

Patent Opposition vs Patent Revocation Under Section 64

Patent opposition should also be distinguished from revocation proceedings under Section 64 of the Patents Act. Section 64 permits a patent to be revoked on a petition by a person interested or the Central Government, and also permits revocation to be sought by way of a counterclaim in a patent infringement suit. The grounds for revocation substantially overlap with the grounds available under Section 25.

Following the abolition of the Intellectual Property Appellate Board (IPAB) through the Tribunals Reforms Act, 2021, jurisdiction over patent revocation petitions that was previously exercised by the IPAB now lies with the High Courts. Section 104 also provides that where a defendant raises a counterclaim for revocation in a patent infringement suit, the suit and counterclaim are to be transferred to the High Court for decision. The distinction is therefore not merely procedural. A party considering a patent validity challenge must assess the appropriate forum and the stage at which the challenge is being pursued.

What Did the Supreme Court Hold in Aloys Wobben v. Yogesh Mehra?

The Supreme Court’s decision in Dr. Aloys Wobben v. Yogesh Mehra, (2014) 15 SCC 360, is important when considering the relationship between different patent validity challenges. The Supreme Court considered whether a party could simultaneously pursue multiple remedies under Section 64 for revocation of the same patent. The Court held, in substance, that where a party has already pursued one of the available Section 64 remedies, it cannot subsequently pursue an inconsistent alternative remedy in respect of the same patent.

The judgment also considered the effect of a post-grant opposition under Section 25(2) and observed that a person who has initiated such proceedings cannot subsequently pursue a revocation petition or counterclaim seeking revocation of the same patent.

Accordingly, the sequence in which a patent validity challenge is initiated can be strategically significant. Parties should evaluate the available statutory routes before commencing proceedings rather than treating post-grant opposition, revocation and counterclaims as freely interchangeable remedies.

At the same time, Aloys Wobben should not be read as creating an absolute prohibition on a patentee instituting infringement proceedings while a post-grant opposition is pending. In AstraZeneca AB v. Westcoast Pharmaceutical Works Ltd., the Delhi High Court examined this issue and held that the pendency of a post-grant opposition does not, by itself, prevent a patentee from instituting an infringement action after grant.

Patent Opposition and Infringement Proceedings

A patent owner may institute infringement proceedings after the patent has been granted. If a defendant seeks to challenge the validity of the patent in an infringement suit, Section 104 permits a counterclaim for revocation, following which the suit and counterclaim are transferred to the High Court. This creates an important strategic distinction between a post-grant patent opposition, an independent Section 64 revocation petition, and a counterclaim for revocation in patent infringement litigation.

For a potential competitor, the relevant considerations may include the stage of the patent, the commercial launch timeline, the opponent’s standing, the evidence available to challenge validity and the possibility of subsequent infringement litigation.

For a patent owner, the timing and nature of a challenge may affect prosecution strategy, litigation planning and the evidence required to defend the validity of the patent.

Which Patent Opposition Route Should Be Considered?

There is no universally applicable route for challenging a patent. The appropriate mechanism depends on the stage of the patent application or grant and the circumstances of the party seeking to challenge validity.

A pre-grant opposition may be relevant where the patent application has been published but the patent has not yet been granted. Its broad standing requirement allows any person to file a representation, subject to the statutory procedure and prima facie assessment.

A post-grant opposition becomes relevant after grant and must be filed within one year from publication of the grant. However, the opponent must qualify as a person interested.

Once the patent is granted, a party may also need to consider revocation under Section 64 or, where an infringement suit has been instituted, a counterclaim for revocation. The Supreme Court’s decision in Aloys Wobben makes it particularly important to assess the procedural consequences of choosing one remedy over another.

Conclusion

Pre-grant and post-grant patent oppositions are important mechanisms for challenging patent rights in India, but they operate at different stages and impose different standing, procedural and financial requirements.

The Patents (Amendment) Rules, 2024 have significantly changed the pre-grant opposition process by introducing a prima facie assessment, reducing the applicant’s response period to two months, providing for expedited examination where the prescribed conditions are met and introducing filing fees.

At the post-grant stage, the one-year limitation for filing an opposition and the requirement that the opponent be a “person interested” make timing and standing particularly important. The availability of Section 64 revocation proceedings and counterclaims in infringement suits further requires parties to assess the consequences of selecting a particular patent validity challenge.

For businesses, innovators, patent owners and potential competitors, understanding the patent opposition procedure in India, applicable deadlines, filing fees and the interaction between Section 25 opposition and Section 64 revocation is therefore critical to developing an effective patent prosecution and litigation strategy.

Frequently Asked Questions

Last Updated on 30 September, 2026