Last updated: 
30 May 2016

If you believe an invention should not be awarded a patent, you can challenge its validity by filing an opposition.

Patent oppositions can be made against:

  • an accepted standard patent application
  • a certified innovation patent

Apart from the granting of a patent, other actions in the patent application process can be opposed including:

  • an applicant's request to amend their patent specification
  • the grant of an extension of time to restore a patent or patent application
  • the grant of an extension of term of a pharmaceutical patent
  • the grant of a licence to use an invention

Reasons for opposing the grant of a standard patent

The most common reason for opposing the grant of a standard patent is that the invention claimed in the application is not new and/or inventive. Other reasons may also be given, including contesting the ownership of the invention.

When to file a patent opposition

If you want to oppose a patent or patent application you must file a notice of opposition with us. Given the cost and complexity of these proceedings, it is advisable to obtain professional advice before you file a notice of opposition.

A notice of opposition to the grant of a standard patent application must be filed within three months of us publishing the acceptance of an application. A list of accepted applications is published weekly in the Australian Official Journal of Patents (supplement).

An innovation patent may be opposed at any time after it has been certified. The certification of innovation patents is also published in the Australian Official Journal of Patents (supplement).

The time frames for opposing other actions vary. Further details can be found in the Patents Act 1990.

The cost of opposing a patent

We charge administrative fees for filing the notice of opposition, for appearing at the hearing and for an extension of time if requested.

However, the most significant costs are likely to be for getting legal advice, engaging a legal representative (if you decide you need one) and for the preparation of evidence. Costs for the preparation of evidence will include engaging relevant technical experts.

While the successful party is generally entitled to an award of its costs, this award is normally limited by the legislation and usually amounts to a small proportion of the amount spent by the successful party during the opposition process. The benefit of succeeding in an opposition is that you will be free to carry on your business without risk of infringing the other patent. If you are unsuccessful, you may also be liable for the other party's costs.

What you will have to prove

When an opposition is filed, the patent applicant and the opponent each have an opportunity to provide evidence to the Commissioner of Patents to support their case.

As an opponent, you will need to prove the grounds of opposition that you are arguing. For instance, if you argue that a patent lacks or an inventive/innovative step, you will need to provide copies of any relevant documents and explain how they support your argument. You will need to provide evidence for each ground of opposition.