Patent Oppositions Procedure in Australia

Patent oppositions occur infrequently however it is important to be aware of them and to know any strategic advantages or issues that can arise.

Information for Applicants/Patentees


What to do if your patent/patent application is being opposed

If your patent is being opposed, speak to your registered patent attorney. They will review the Notice of Opposition, Statement of Grounds and Particulars and any Evidence in Support, and provide you with suitable advice for responding.

If I lose an opposition, what can I do?

If you lose an opposition, you may be provided with an opportunity to amend the claims of the patent/application to address issues raised by the decision.  Third parties will be provided an opportunity to oppose any amendments proposed prior to them being incorporated into the specification.

Information for Opponents

When to file an opposition

If you wish to oppose a standard patent application/innovation patent a Notice of Opposition must be filed within 3 months of the Notice of Acceptance issuing in relation to the relevant patent application, or any time after certification of the relevant innovation patent.

How to file an opposition

An Opponent will need to file following documents to commence opposition proceedings:

   1. A Notice of Opposition – essentially provides the essential details of the type of opposition, parties and right involved.

   2. A Statement of Ground and Particulars – outlines the reasons for the opposition and include all of the facts and circumstances being relied upon. 

These documents will be forwarded onto the Applicant/Patentee.

Brief Opposition Procedure Outline

Commencing opposition proceedings

An Opponent will need to file a Notice of Opposition and Statement of Ground and Particulars to commence opposition proceedings.


Once an opposition has been commenced, i.e. once the Notice of Opposition and the Statement of Ground and Particulars has been filed/received, an evidence phase will commence.  During this phase, the Opponent has an opportunity to file Evidence in Support (standard applications only), the patentee/applicant subsequently has an opportunity to file Evidence in Answer; and, the opponent has a further opportunity to file Evidence in Reply. 


Once the evidence phase ends, IP Australia schedules a hearing date.  Hearings may be based on written submission only, or on an oral hearing in addition to written submission being filed.  Hearings take place before a hearing officer.


Once the hearing concludes, a decision is issued thereafter by the hearing officer based on the submissions made at the hearing and the evidence filed.

Copies of past decisions are published on the Australasian Legal Information Institute website.


Once a decision has been issued, either party has an opportunity to file an appeal.  Appeals from opposition decisions are made to the Federal Court of Australia.


Certain timeframes need to be met at most stages of the opposition process. Some timeframes are set by IP Australia and some are set by legislation.

AU patent procedure flow chartinnovation patent procedure flowchart AU

written by Sarah van der Waal, Associate