In The NOCO Company v Brown and Watson International Pty Ltd [2026] FCAFC 44, the Full Court of the Federal Court has affirmed previous decisions that the relevant date for assessing a patentee’s disclosure of the best method under s 40(2)(aa) of the Patents Act 1990 is the date of filing the patent in suit, not any earlier priority or parent document.
- The decision has direct consequences for patentees with divisional patents, particularly in fast-moving industries, as the relevant date is the filing date of the complete specification of the divisional. Divisionals may be vulnerable where a patentee has improved commercial products embodying the patents since filing earlier PCT or parent applications, and the improvements reflect a better method of performing the invention.
- R&D and commercial teams should keep IP counsel updated about key improvements to relevant commercial products, particularly if divisionals are a key part of patent strategy.
- Revoking parties should investigate whether any improvements to the patentee’s commercial products made before filing a divisional indicate that there was a better method of performing the invention that has not been disclosed in the complete specification of the divisional.
Background
The appellant (NOCO) owns several patents relating to jump starters for boosting a depleted or discharged battery (such as a car battery), each of which was a divisional patent. NOCO sued the respondent (B&W) for patent infringement, and B&W cross-claimed alleging invalidity.
In relation to best method, there was evidence that between the filing of the PCT application and the later divisionals in suit, NOCO made certain improvements to its commercial products embodying the patents. The main contest was whether the relevant date for assessing disclosure of the best method was the filing date of the priority document (NOCO’s position), or the filing date of each divisional (B&W’s position). Some findings in Rescare Ltd v Anaesthetic Supplies Pty Ltd (1992) 25 IPR 119 (Rescare) (cited with approval in later Full Court authorities) appeared to support NOCO’s position. However, a single judge decision in Dometic Australia Pty Ltd v Houghton Leisure Products Pty Ltd [2018] FCA 1573 (Dometic) expressly held that the relevant date was the filing date of the divisional patent.
Findings
At first instance, the primary judge found that the ‘complete specification’ referred to in s 40(2)(aa) was the complete specification of the earlier priority document, being a PCT application. Given the monopoly ran from the date of filing the PCT application, His Honour considered that this was the relevant date ‘by parity of reasoning’ to Rescare, in which Gummow J made the following findings in relation to the Patents Act 1952:
[The 1952 Act] provided for a term of a standard patent of 16 years, reckoned from the date of the patent, this being the date on which the complete specification was lodged. The adequacy of the disclosure should be judged by reference to the time from which dated the monopoly granted the applicant in exchange for the disclosure. In the present case that is the international filing date, 23 April 1982. This is the date from which the term of the patent runs.
The primary judge reasoned that Rescare was supported by the later Full Court cases of Pfizer Overseas Pharmaceuticals v Eli Lilly & Co [2005] FCAFC 224 and Les Laboratoires Servier v Apotex Pty Ltd [2016] FCAFC 27, which referred to this passage with approval. While White J in Dometic made clear findings consistent with B&W’s position, the primary judge considered that he was bound to follow Pfizer.
In obiter, the Full Court disagreed with the primary judge’s characterisation of the cases. The Full Court considered that Rescare did not stand for the proposition that the relevant date was the date from which the patent runs. Rather, the ‘central thrust’ of the Rescare analysis was that ‘the operative date is the date of lodging the complete specification’, consistent with the statutory language in the provision. Their Honours indicated that Pfizer and Servier cited Rescare for the proposition that disclosure must be made at the filing of the complete specification, not when the patent monopoly starts to run.
Although s 29A(2) of the Patents Act provides that a PCT application may be a complete specification, the Full Court noted that this does not mean it is the complete specification referred to in s 40(2). In particular, s 40(2) is directed to the complete specification of the patent sought to be revoked.
Implications
The Court has committed to a clear position regarding the date of assessment for best method in relation to divisional patents, being the date of filing the complete specification for the divisional patent in question. This is consistent with the language of the relevant statutory provision, such that any alternative position would require legislative amendment. While the best method requirement remains an important feature of Australia’s patent law, any appetite by the legislature to amend the provision may re-enliven the question of whether the best method requirement should be abolished (which would bring Australia in line with other key jurisdictions).
For now, the best method obligation remains a very strong ground for revoking parties, not only for its scope and ability to invalidate the entire patent, but also being one of the few grounds in respect of which courts are typically willing to permit discovery. In light of the Full Court’s decision, patentees with active patent families incorporating divisional applications (particularly in fast-moving technology areas) should continually assess whether later developments, fixes, choices or improvements have become the best known method of performing the claimed invention.
