The patent opposition system recognises that the examination process is imperfect. Examiners have limited time, resources and technical expertise. Therefore, they may not always find the closest and most relevant prior art, or spot every technical and legal issue that might be identified by a motivated competitor to the patent applicant, equipped with a team of technical and legal experts. Furthermore, opposed applications are presumably those that are of greatest concern to competitors, enabling the system to weed out invalid claims that have the greatest potential to unfairly stifle competition.
In the years prior to 2016, the number of oppositions filed each year was fairly consistently between 100 and 120. In recent years, however, it has commonly been between 40 and 60. In other words, there are now only about half the number of patent oppositions being filed than was the case just a decade ago. So, if oppositions play an important role in the Australian patent system – and the policy rationale for having them asserts that they do – is it possible that they are now less effective than they once were? And, if so, then why?
In this article, I will present data on all patent oppositions filed between 2008 and 2023. I will demonstrate that the decline in patent oppositions appears to be associated with the commencement of the Raising the Bar (‘RtB’) IP law reforms in 2013. Among other things, the RtB reforms introduced more stringent standards of patentability, particularly in relation to inventive step and the level of disclosure required to support broader patent claims. The reforms also changed the standard of proof to be applied during examination and opposition proceedings. I will show that in the post-RtB era, opposition proceedings have more frequently progressed through to a final decision, and that opponents have had somewhat greater success in completely eliminating opposed applications. However, the overwhelming majority of opposed applications still result in granted patent rights, and in nearly half of all cases the opponent has been wholly unsuccessful and the patent has been granted with the originally accepted claims.
While the data cannot directly reveal the reasons for the significant reduction in opposition filings, I tentatively argue that the change in the standard of proof applied in patent oppositions may have had the unintended consequence of suppressing patent oppositions, and reducing the effectiveness of the opposition system.
As I recently reported, 
Over the past five years (i.e. since 2019) Korea’s LG Electronics Inc and China’s Huawei Technologies Ltd have consistently placed in the top five applicants for Australian patents. Indeed, for the past four years they were in the leading three. In 2021, 
In 2023 the total number of standard patent applications filed in Australia remained above 30,000 for the third year running, despite a 2.4% drop in filings. This follows a decline of nearly 0.5% in the previous year. However, whereas the decline in new applications in 2022 was due to fewer filings by Australian residents (with a slight increase in foreign-originating applications preventing a larger fall), the drop in 2023 was the result of nearly 800 fewer filings by foreign applicants. As always, a majority of new filings were national phase entries (NPEs) derived from international applications under the Patent Cooperation Treaty (PCT). But, for the first time since 2016, the number of PCT NPEs fell – by 3.2% – offset somewhat by a 14% rise in new direct national filings. The number of divisional applications also fell in 2023, by 7.3%.
