Opposing a Patent Application

A patent opposition is an adversarial mechanism provided in the Patents Act for a third party to oppose the grant of a standard patent or the certification of an innovation patent. Any person (opponent), such as a competitor, supplier or customer, can lodge and progress an opposition to a Hearing at IP Australia (rather than the Courts) to prevent invalid intellectual property rights from being awarded to the patentee (applicant).

The examination of patents is a broad sieve to eliminate invalid patents being granted but cannot work perfectly regardless of how thorough a search is conducted, as not all prior art is readily available to the Examiner. Through the patent opposition system, a finer review is possible as the opposition Hearing Officer can be made aware of information that may not have been readily available to the Examiner or can be directed to other prior art information from around the world that was not found during the examination process.

The legislator recognises two basic functions of the patent opposition system:

  • to improve the likelihood that only valid patents are granted or certified; and
  • to provide a simpler, more efficient, and less costly alternative to Courts to settle determination of scope of valid IP rights for granted patents.

In this manner, any expenditure on post-grant enforcement of those IP rights, including against an infringer of the intellectual property is less financially risky.

Strategy prior to patent opposition

It is important before launching into a patent opposition system to review the case carefully to ensure this is the best approach. Those review steps include determining:

  • What is the commercial result being sought?
  • What are the technical arguments on patentability to be used in the patent opposition?
  • What needs to be done to present an opposition thoroughly?
    • Is a detailed search required?
    • Is a detailed validity opinion required?
    • Is Barrister representation valuable?
    • Is independent expert evidence required?
  • Is success likely and what are the costs?
  • Is there a better patent approach or more effective procedural mechanism?

Commercial strategy alongside or instead of patent opposition

It is easy to blindly proceed along a legal path not carefully aligned with commercial objectives. However, the project or business objectives are always the primary concern.

At Baxter IP, we start contentious matters by setting our legal knowledge, skill and experience to one side and instead probe to gain a deep understanding of the business, the other side, any competing products, the market and the actual commercial case for the opposition.

The commercial result required drives our approach to the patent opposition. However, it is important to determine how else that commercial outcome might be achieved. Some commercial matters to be considered are:

  • Is the commercial aim to stop others using the invention in the relevant industry or to allow you to operate using the invention in the industry or in a similar industry?
  • Are you trying to coexist with the commercial opponent or obtain a commercial advantage over the opponent?
  • Is negotiation with an indication of strength of position supported by the ability to lodge patent opposition (but without actually lodging the opposition) a viable commercial approach?
  • Is there a commercial effect on your business, including your wider business community such as distributors, that is affected by this legal matter?
  • Has the balance of commercial cost effectiveness of lodging an opposition been assessed.

Overview of patent opposition

In general, the objectives of patent opposition are:

  1. To reduce the probability of an invalid patent being granted;
  2. To give the examiner the opportunity to scrutinise evidence or documents that would not have otherwise been available (or readily available) without the opposition proceedings;
  3. To avoid costly patent litigation post patent grant; and/or
  4. To enable possible clarity to commercial parties as to the valid scope of claims when a patent becomes enforceable.

Grounds for patent opposition

Possible grounds for patent opposition include:

  1. If the nominated person
    • is not entitled for patent grant according to section 33(1)
    • is entitled for grant only with another person
  2. If the invention itself is not patentable, such as
    1. The invention is not a manner of manufacture
    2. Compared to prior art,
      • the invention is not novel; or
      • the invention does not involve an inventive step
    3. The invention was secretly used before the priority date of the patent claim by, on behalf of or as authorised by the patentee, a nominated person, or any of their predecessors.

When is a patent opposition lodged?

For an Australian standard patent, patent opposition can be filed at any time from publication of acceptance of the patent application to three months from that date. An opposition to an Australian Innovation Patent can be filed at any time after it has been certified.

Overview of patent opposition procedure

Patent Opposition Procedure
Patent Opposition Procedure

Documents and evidence provided in patent applications

In the Statement of Grounds and Particulars, the opponent must keep in mind and be as comprehensive as possible when filing the document because amendment can only be requested to address clerical errors. In addition, the type of evidence provided in the second stage of patent opposition should depend on the ultimate goal of the opposition, and the submissions must be detailed and comprehensive enough to aid the Patent Office in assessing the matter. Thus, the aid of a patent attorney who is well-versed in patent oppositions is crucial in preparing the documents and evidence to be filed in order for your patent opposition goals to be met.

Hearing of Opposition

It should be remembered that the case is NOT argued in the evidence. The evidence is the factual matters that support your legal arguments. The legal case is presented at the Hearing and the various parts of the evidence are:

  • Evidence in support of the opposition, which is provided by the opponent;
  • Evidence in answer, which is provided by the applicant; and
  • Evidence in reply, which is provided by the opponent.

Evidence presented in these sections serve highly specific functions. Evidence in support should be in the confines of and reinforce the case as stated in the statement of grounds in particulars. Evidence in answer is the main time for the applicant to provide their evidence in response to the opposition grounds, particulars and evidence in support. Evidence in reply, which is supplied by the opponent, should only serve to rebut the evidence in answer submitted by the applicant in response to the evidence in support of the opposition; it should not raise a new argument that should have been presented in the evidence in support and should not contain merely confirmatory statements supporting the existing evidence.

It can therefore be seen that the whole process of the Opposition must be considered and planned at the start and reviewed throughout the process. Knowledge experience and forward planning skills are required and provided well by the expert Opposition teams at Baxter IP.


The Opposition process is a process out of the Courts in an Administrative law setting of IP Australia. However there are possible appeals to the Administrative Appeals Tribunal (AAT) or the Federal Court within a very restricted appeal timeline (usually 21 – 28 days).

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