Patent Opposition

What is Patent Opposition?

Patent opposition is a legal process where a third party challenges the validity of a granted patent or a pending patent application. The goal is to prevent the grant of a patent that does not meet the legal requirements of patentability, or to revoke or limit the scope of an already granted patent.

Types of Patent Opposition

1. Pre-Grant Opposition:
  • Filed by a third party against a patent application before the patent is granted.
  • The opposition must be filed after the publication of the patent application and before the grant of the patent.
  • Common grounds for pre-grant opposition include lack of novelty, lack of inventive step, insufficient disclosure, and non-patentable subject matter.
2. Post-Grant Opposition:
  • Filed by a third party against a granted patent within a specified period after the grant (usually within 12 months from the date of grant).
  • Grounds for post-grant opposition are similar to those for pre-grant opposition, such as lack of novelty, lack of inventive step, non-patentable subject matter, insufficient disclosure, and prior public use.

Pre-grant opposition in India

  • Section 25(1) of the Indian Patent Act, 1970 along with Rule 55 of Patents Rules, 2003 lays down the law relating to pre-grant opposition in India. The opposition can be filed by any person in writing, any time after the publication of the patent application and before it is granted. It is necessary to obtain the complete specification from the official website as opposition cannot be made solely based on the abstract. The purpose of this mechanism is to act as a defensive shield that verifies the validity of the application before the actual grant of patent rights. The opposition is known as making a “representation.”
Grounds for pre-grant opposition

Section 25(1) clauses (a) to (k) of the Patent Act lays down an exhaustive list of the grounds based on which the patent application can be opposed. These grounds are:

1. Wrongful obtainment:
  • The invention or any part thereof was wrongfully obtained from the opponent.
2. Prior publication:
  • The invention was published before the priority date (earliest filing date which discloses the invention). This objection is subject to Section 29 of the Act, which talks about situations where the publication does not constitute an anticipation of the product or process.
3. Prior claim:
  • The invention was previously claimed in another Indian patent application, which was published on or after the priority date of the applicant’s claim but whose priority date is earlier than that of the applicant.
4. Prior knowledge or use:
  • The invention is known or used by the public before the priority date. In the case of a process that is being patented, it is deemed to have been publicly known or used if a product made by that process was imported in India, before the first date of filing of the application.
5. Obviousness:
  • The invention is obvious and does not involve any inventive step. This means that no advancements have been to the existing use or literature on the subject.
6. Non-patentable subject matter:
  • The subject of the application is not considered to be an invention under the Patent Act or falls in the category of “non-patentable inventions”.
7. Insufficient description:
  • The patent specification does not properly explain the invention or the method of performing it.
8. Non-disclosure:
  • The applicant has failed to disclose all the details which were required under Section 8 of the Act.
9. False disclosure:
  • The applicant has provided materially false information.
10. Time limit:
  • The conventional application was not filed within the specified period of 12 months from the date of the first patent application made in a conventional country.
11. Biological material:
  • The specification failed to disclose the origin or source of the biological material, if any, used in making the invention or has mentioned the incorrect source.
12. Traditional knowledge:
  • The invention was anticipated taking into consideration the knowledge possessed by indigenous communities anywhere in the world.
Procedure for pre-grant opposition
  • The procedure for filing a patent opposition is outlined in Rule 55 of the Patent Rules. This rule specifies that all opposition representations must be submitted using Form 7A of the Act to the Controller General of Patents. The Indian legislature has included a provision that prevents the granting of patents until six months have passed since the date of publication. This allows a sufficient timeframe for third parties to file an opposition. If the examiner deems the arguments in the opposition statement to be without merit, the opposition will be dismissed through a detailed order. Conversely, if the statement is found to be valid, the examiner will notify the applicant. The applicant must then provide their own statement and any evidence within three months from the date of the notice. The Controller will review the statements and issue a detailed order, which may result in the following outcomes:

I. granting the patent

ii. refusing the patent

iii. or requiring amendments to the patent specification or other documents before the patent can be granted.

Post-grant opposition in India

  • Once the patent has been granted, there is still a way for third parties to oppose the grant. This was done by way of a ‘notice of opposition’. The notice has to be filed with the Controller of the appropriate patent office at any time within 12 months from the date on which the grant of the patent was published in the Indian Patent Journal.
  • Unlike pre-grant opposition, this type of opposition can only be filed by an “interested party”. Section 2(1)(t) of the Patent Act, 1970 gives an inclusive definition of the term “person interested. ” It includes an individual involved in or promoting research in the field to which the patent pertains. It may also refer to an entity that has a manufacturing, trading, or financial interest in the patented goods.
Grounds for post-grant opposition
  • Under the Act, there is no difference in the grounds on which pre-grant and post-grant oppositions can be made. Section 25(2) specifies the same grounds which were listed in subsection 1 of the provision. Nevertheless, there are substantial differences in the procedures of both the oppositions, which will be discussed in the following sections.
Procedure for post-grant opposition
  • Rules 55A to 70 of the Patent Rules, 2003, outline the procedure for filing a post-grant opposition. To initiate an opposition under Section 25(2), a notice must be submitted to the Controller at the relevant patent office using Form 7.

How to Overcome Patent Oppositions

1. Analyze the Opposition:
  • Thoroughly review the opposition notice and the grounds on which the opposition is based.
2. Gather Evidence:
  • Collect all necessary evidence and documents to refute the claims made in the opposition. This may include prior art references, expert opinions, and technical data.
3. Prepare a Detailed Response:

Draft a comprehensive response addressing each ground of opposition. This includes:

Legal Arguments:
    • Highlighting the legal aspects that support the validity of the patent.
Technical Arguments:
    • Providing technical explanations and evidence to counter the opposition claims.
    • Making necessary amendments to the claims or specification to overcome the objections raised.
4. Engage in Hearings:
  • Participate in hearings, if required, to present arguments and evidence before the opposition board or relevant authority.
5. Negotiation and Settlement:
  • In some cases, it may be possible to negotiate with the opposing party to reach a settlement or agreement.

Why a Professional is Important for Patent Oppositions

1. Expert Knowledge:
  • Patent attorneys have in-depth knowledge of patent law, procedures, and requirements, enabling them to effectively navigate the opposition process.
2. Strategic Response:
  • Professionals can develop strategic responses and arguments that are tailored to address the specific grounds of opposition.
3. Evidence Collection:
  • Patent attorneys can assist in gathering and presenting the necessary evidence to support the validity of the patent.
4. Legal Representation:
  • In hearings and negotiations, having a professional represent you can significantly enhance your position and chances of success.
5. Technical Expertise:
  • Patent professionals often have technical backgrounds that allow them to understand and argue the technical aspects of the invention effectively.
6. Procedural Compliance:
  • Ensuring that all procedural requirements and deadlines are met is crucial in opposition proceedings. A professional can manage these aspects efficiently.
7. Negotiation Skills:
  • Experienced patent attorneys can negotiate with the opposing party, potentially finding common ground or resolving disputes without extensive litigation.


  • Patent opposition is a crucial process for challenging the validity of patents, either before or after they are granted. Overcoming opposition involves a detailed analysis of the opposition grounds, gathering evidence, preparing a robust response, and potentially participating in hearings. Engaging a professional patent attorney is essential due to their expertise, strategic thinking, and ability to navigate the complex legal and technical aspects of patent opposition proceedings effectively.

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