AU divisional patent applications require an up-to-date ‘best method’

Ben MottMay 27, 2026

Patent applications require up-to-date best method

An update for patent attorneys.

Australian patent applications must “disclose the best method known to the applicant of performing the invention” [1]. This requirement was long understood to mean the best method known to the applicant as at the first Australian non-provisional filing date (e.g. as at the international filing date). As a consequence, in line with routine practice elsewhere, it was entirely routine simply to recycle the original text and figures (perhaps with revised claims) when filing Australian divisional patent applications.

In 2018, a first-instance decision [2] cast doubt on this long-understood meaning. Whilst another first-instance decision [3] in 2025 signalled a return to convention, that decision has now been relevantly overturned on appeal, NOCO [4]. The appeal confirms:

an Australian divisional patent application must disclose the best method known to the applicant as at the filing date of the divisional patent application.

There is no simple formulaic approach to determining that requisite degree of disclosure. Authority suggests “The patent applicant is required to disclose information not already known to the skilled addressee by way of the common general knowledge” [5], but that there is no need to disclose “inessential manufacturing and production information applicable to the commercial embodiment”[6].

In Sandvik [7], the appeals court set out the applicable principles (see paragraphs 93 to 114) and concluded that discussion with:

For present purposes, the following key principles may be stated on the basis of the authorities set out above:

The purpose of the requirement in s 40(2)(a) to disclose the best method known to the applicant of performing the invention is to allow the public the full benefit of the invention when the monopoly expires: Servier 8 at [108].
Although a patentee might not be explicitly required to act in good faith, principles of good faith underlie the best method requirement: Servier at [108].
The nature and extent of the disclosure required to satisfy the best method requirement will depend on the nature of the invention itself: Firebelt 9 at [52]-[53]; Servier at [108].
The key to understanding the obligation of the patentee is to understand that the section is directed to the method of performance of the invention. The monopoly is circumscribed by the claims, but the nature of the invention is as described in the whole of the specification: Servier at [124].
The requirement to describe the best method of performing the invention is ordinarily satisfied by including in the specification a detailed description of one or more preferred embodiments of the invention: Firebelt at [53]; Servier at [104]. See also Blanco White (5th ed) at [4-516]; Bodkin C, Patent Law in Australia (2nd ed, Thomson Reuters, 2014) at [5280].

(Footnotes added)

Sandvik concerned an extension drilling system claimed in the following terms:

An extension drilling system for use with a semi-automatic drilling rig, said drilling system including a plurality of extension rods connected together to constitute a drill rod string and each extension rod having a male right-hand rope threaded coupling at one end and a female right-hand rope threaded coupling at the other end, whereby the extension rods are connected together by coupling of the male coupling of one extension rod with the female coupling of another extension rod to create a male/female coupling between extension rods, a drive chuck of a drilling rig for driving the outside surface of a female coupling of an extension rod at one end of the drill rod string, in either forward or reverse direction, a set of grippers for preventing rotation of an extension rod being arranged to clamp an extension rod at a location such that only one male/female coupling is located between the drive chuck and the set of grippers and so that with the grippers clamping the extension rod, and with the drive chuck being driven in the reverse direction, the male/female coupling between the grippers and the drive chuck is uncoupled.

Evidence showed that there had been difficulties when designing a seal that “was necessary and important to carry that invention into effect” [10].

In the part of the Reasons dealing with the best method issue, the primary judge stated in connection with the sealing member:

“[w]e are not here dealing with some minor or incidental dimension of what was perceived by the inventors as the best method of performing the invention: as Mr Weaver said, this sealing aspect was ‘a real issue which needed to be overcome’” (Reasons, [224]). This was clearly a reference back to the evidence of Mr Weaver described in [104] of the Reasons (and set out at [119] above). In light of that evidence, it was certainly open to his Honour to conclude that the use of an adequate water seal was a critical (rather than a minor or incidental) aspect of the best method of performing the invention. [11]

The specification included scant detail of the seal, and an upwardly-extending spigot of the seal was only disclosed Figure 3:

The disclosure of the seal and its upwardly-extending spigot was held to be insufficient, and on this basis the patent was held to be invalid. From the first instance decision:

Did the specification describe a method of performing water sealing in the adaptor shown in Fig 3 by means of a sealing member which included an upwardly-extending spigot integral with the flat part of the member? The starting point, of course, is the text of the specification. The sealing member described there is confined to the stainless steel washer body coated in polyurethane. The sealing member is numbered 21j and, while there is some ambiguity about the matter, most obviously this is a reference to the horizontal element. That was Dr Fuller’s understanding. Mr Charlton was able to discern what the inventors were about in this aspect of Fig 3, but his understanding of the subject depended to an important extent on what he regarded as implicit: in a metaphorical as well as a literal sense, he was required to join the dots. In my view, for the inventors to have communicated in this way to the skilled addressee did not amount to a description within the meaning of s 40(2)(a) of the Act: no more so in the case of the best method than it would have been in the case of the invention itself. [12]

NOCO concerned an XXX claimed in the follow terms:

Claim 1 of the 338 Patent is in the following terms (with numbers added for ease of reference):

(1.1) A jump starting device for boosting or charging a depleted or discharged battery having a positive battery terminal and a negative battery terminal, the jump starting device comprising:

(1.2) a rechargeable battery;

(1.3) a positive battery connector for electrically connecting the jump starting device to the positive battery terminal of the depleted or discharged battery;

(1.4) a negative battery connector for electrically connecting the jump starting device to the negative battery terminal of the depleted or discharged battery;

(1.5) a power switch or switch circuit connected in series with the rechargeable battery and the positive and negative battery connectors, the power switch or switch circuit configured to switch power on from the rechargeable battery to boost or charge the depleted or discharged battery when connected between the positive and negative battery connectors;

(1.6) a USB input connector; and

(1.7) a USB charge circuit electrically connecting the USB input connector to the rechargeable battery, the USB charge circuit comprising a DC-DC converter configured to upconvert voltage from the USB input connector to the rechargeable battery. [13]

(Our emphasis)

A commercial embodiment of the invention, referred to as “GB30”, had significant technical problems and was updated after its initial release:

“(a) The GB30 as launched used a lithium ion battery pack and generated a continuous discharge current of 25C and a burst discharge current of 50C. The battery discharge capability was considered insufficient and the size of the battery was increased.

(b) The GB30 as launched used three FETs in parallel. However, problems were experienced with the FETs and they were replaced with relays.” [14]

The divisional patent, filed after these technical updates, was held to be invalid because it did not disclose these technical updates.

Conclusions

The best method requirement is a live issue in Australia.
It is important to prepare an updated patent specification for each successive divisional patent application.
The solutions to all real technical issues associated with the preferred embodiment must be disclosed, regardless of whether those solutions correspond to integers recited in the claim.

[1] Section 40(2)aa of the Patents Act 1990

[2] Dometic Australia Pty Ltd v Houghton Leisure Products Pty Ltd [2018] FCA 1573

[3] The NOCO Company v Brown and Watson International Pty Ltd [2025] FCA 887

[4] The NOCO Company v Brown and Watson International Pty Ltd [2026] FCAFC 44

[5] Paragraph 186, GlaxoSmithKline Consumer Healthcare Investments (Ireland) (No 2) Limited v Generic Partners Pty Limited [2018] FCAFC 71

[6] Paragraph 225, The NOCO Company v Brown and Watson International Pty Ltd [2026] FCAFC 44

[7] Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd [2017] FCAFC 138

[8] Les Laboratoires Servier v Apotex Pty Ltd [2016] FCAFC 27

[9] Firebelt Pty Ltd v Brambles Australia Ltd & Ors [2000] FCA 1689

[10] Paragraph 126

[11] Paragraph 122, Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd [2017] FCAFC 138

[12] Paragraph 219, Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd [2016] FCA 236