Best method requirement in Australia
In Australia, patent applicants must disclose the best method known to them of performing the claimed invention at the date of filing a complete (non-provisional) application. Notably, New Zealand also retains a similar best method requirement and, unlike in the United States, best method is a ground of opposition and revocation in both jurisdictions (although the case law in New Zealand is less developed in this regard).
Since 2016, when the Full Federal Court in Les Laboratoires Servier v Apotex Pty Ltd [2016] FCAFC 27 confirmed that the best method requirement is residual to the requirement for sufficiency of disclosure, it has become a very popular – and often successful – ground of revocation for patents drafted without this unique requirement in mind.
Level of disclosure required
Following Servier, the courts have grappled with the level of disclosure necessary to satisfy the best method requirement. In BlueScope Steel Limited v Dongkuk Steel Mill Co., Ltd (No 2) [2019] FCA 2117, in which the patents at issue were revoked for failure to disclose the best method, the court set out some helpful guidance at [836]-[837]:
The best method requirement will be satisfied if the skilled person can arrive at the best method known to the applicant of performing the invention by some routine experimentation and without ingenuity or undue experimentation.
- The specification must disclose each essential element or feature for performing the invention, even if the skilled person would know or could readily ascertain that element.
- Specific details of the method that would be well-known and understood by the skilled person need not necessarily be disclosed. However, the requirement will not be satisfied if the skilled person is left to make a choice (e.g., what analytical agent or equipment to use) or is left in doubt as to what a term means, where that choice or uncertainty affects the performance of the method.
- If the best method requires a step that is omitted by the complete specification, even if it could be readily ascertained by the skilled person, the best method requirement will not be met.
Essentially, the nature and extent of the disclosure required to fulfil the best method requirement depends on the nature of the invention itself, which is to be discerned from the whole of the specification, including the claims (Servier, Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd [2017] FCAFC 138; Zoetis Services LLC v Boehringer Ingelheim Animal Health USA Inc [2024] FCAFC 145). However, it is not necessary to identify in the specification which method is in fact the “best” one.
Recent relief for divisional applications
Interestingly, in 2018, a single judge of the Federal Court found that in the case of divisional applications, the applicant’s knowledge of the best method should be assessed at the time of filing the divisional application (Dometic Australia Pty Ltd v Houghton Leisure Products Pty Ltd [2018] FCA 1573). This meant – contrary to conventional wisdom – that if a better method of performing the invention became known to the applicant between the date of the filing of the parent and its divisional, the divisional application had to be updated at filing to include this better method.
Fortunately, a few months ago, another Federal Court judge effectively disagreed and said the knowledge requirement should be assessed at the effective (ultimate parent application) filing date (The NOCO Company v Brown and Watson International Pty Ltd [2025] FCA 887). While it is possible this issue could be revisited in future, it is widely considered that NOCO represents a much more pragmatic interpretation of the law than Dometic.
Tried to have your cake and eat it too? What you can do
For patent applications with an examination request date on or after 15 April 2013, the only way to rectify a failure to disclose the best method is to file a divisional application (if possible) with the best method added. For patents with an examination request date before 15 April 2013, it may be possible to amend the patent to include the best method, but any undue delay in making such an amendment will weigh heavily against its allowance if court proceedings have already commenced.
The key lesson remains that you cannot have your cake and eat it too when it comes to patent disclosure requirements in Australia or New Zealand, so if either of these jurisdictions is of interest, strategic drafting to include the best method at the outset remains the most effective safeguard against revocation.
This article was first published in October 2025 on IPKat.