One of the most foundational aspects of international patent law since 1883 has been the right to derive an earlier priority date for a national patent application from an earlier filed application. For a profession so focused on establishing novelty and non-obviousness over publications made before that priority date, it is strange that the law on actually determining that priority date is not more settled, and perhaps not more harmonized internationally.
We have recently received affirmation by the Full Court of the Federal Court of Australia in The NOCO Company v Brown and Watson International Pty Ltd [2026] FCAFC 44 of the European approach under Article 87 to assessing priority date that was adopted by Nicolas J in ToolGen Incorporated v Fisher (No 2) [2023] FCA 794.
The priority application must first disclose the “same invention” that the patent applicant hopes to later claim, and must second disclose that invention in a manner clear enough and complete enough for it to be performed by the person skilled in the art.
Harmony in Theory, Friction in Practice
When Australian law-makers Raised the Bar for patent applicants to clear over a decade ago, they revised the relevant standard for assessment of the priority date of a claim to being whether any earlier filed application discloses “the invention in the claim in a manner that is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art”.[1]
The goals of the reforms were to:
(a) ensure the “disclosure in a provisional or other relevant application is [not] less complete than required in a complete specification”;
(b) “align the requirements for securing a priority date with most other major patent jurisdictions”; and
(c) “increase the transparency of the Act” by making the “key aspect (‘clear and complete enough’) of such an important test for priority… explicit in the Act”.[2]
More pointedly, the explanatory memorandum stated that the change “aligns the requirement for securing a priority date from an earlier filed application with the requirement for disclosure in a complete application (see item 8 above)” and that disclosure requirement was intended to align with section 14(3) of the UK Patents Act 1977 and Article 83 of the European Patents Convention.
I was surprised at the time that the language used to assess priority date was not chosen to more closely align with the language of section 5(2)(a) of the UK Patents Act 1977. That language had already been considered and applied by Lord Hoffmann in the seminal decision on priority entitlement of the House of Lords in Biogen v Medeva, and the Australian law-makers had clearly considered that decision in relation to the test for internal disclosure.[3]
To that end, the UK Patents Act section 5(2)(a) uses the language of “support” which was to be included in section 40(3) of the Patents Act 1990. Biogen stood for the proposition that the “clear enough and complete enough” standard for internal disclosure and the “support” standard were not equivalent, and that enabling disclosure was only part of the broader consideration of the technical contribution disclosed in the priority application:
It is not whether the claimed invention could deliver the goods, but whether the claims cover other ways in which they might be delivered: ways which owe nothing to the teaching of the patent or any principle which it disclosed.[4]
It was reasonable to infer from the Raising the Bar reforms that the standard for assessment of priority under Australian law was intended to be less stringent than the standard in the UK for assessing support.
As an aside, slightly later New Zealand aligned itself with the language of “support” for assessing priority entitlement under the UK Patents Act 1977 when enacting the New Zealand Patents Act 2013.
ToolGen does what the Australian law-makers did not
On its face, Australia’s post-Raising the Bar statute looked more generous to patentees—and at odds with the stated policy of aligning priority law with other major jurisdictions.
That apparent divergence has now narrowed sharply.
Beginning with the review of case law undertaken by Deputy Commissioner McCaffery in Grant Fisher v ToolGen Incorporated [2018] APO 65, the bulk of which was adopted by Nicolas J on appeal in ToolGen Incorporated v Fisher (No 2) [2023] FCA 794, Australian law on priority date has been since drawing inexorably into line with Article 87 of the European Patents Convention.
Nicholas J held that while the post-Raising the Bar priority language in s 43(2A) is “essentially the same” as the sufficiency language in s 40(2)(a),[5] as the law-makers had intended, his Honour did not stop there. He rejected ToolGen’s argument that Australian priority law contained no equivalent to the UK/EP notion of also the “same invention”.[6]
Specifically, Nicolas J drew from a line of UK authority including Icescape[7] and Unilin[8], the latter of which comically choosing to ignore the language of the UK Patents Act 1977 and instead choosing to lean heavily on Article 87 the European Patents Convention (EPC) – which explicitly requires the patent claim in question to relate to the “same invention” as the priority application to derive priority from it.
Nicolas J stated at [193]:
Although neither s 43(2A) nor reg 3.13A(2) requires that the invention as claimed be “in respect of the same invention”, it does not follow that the priority document need not disclose the invention claimed. The invention claimed must be disclosed in the priority document if priority is to be obtained. It is not sufficient for the priority document to provide a starting point from which the person skilled in the art may transition from one invention to another by the use of the common general knowledge. The mere fact that it would be obvious to the person skilled in the art to use the disclosure in the priority document to produce what is claimed is not enough to obtain priority if, properly characterised, the priority document and the claim are for different inventions. In this respect, and notwithstanding differences between statutory language in the relevant UK and EPC provisions and s 40(2)(a) of the Act, I consider the position under Australian law is not materially different from the UK law as explained in the English authorities to which I have referred. The question is not what is made obvious to the person skilled in the art from the disclosure of the priority document but what it explicitly or implicitly discloses to that person. The distinction is important even though it is often not easily drawn.
Nicolas J concluded that for section 43(2A)(b) “[a priority document provides the priority date where it discloses] the invention in the claim in a manner that is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art” could be parsed to first require that the priority document must disclose “the invention in the claim” per se.[9]
So although the Patents Act 1990 was specifically redrafted to use the same “clear enough and complete enough” language for both the external priority entitlement and internal disclosure requirements, ToolGen makes clear that this is not enough on its own. An earlier filing does not confer priority merely because it points in the right direction, provides a platform from which the skilled person could reach the later claim using common general knowledge, or makes the later invention obvious or achievable without undue burden. Priority is secured only if the earlier filing directly and unambiguously discloses the same invention later claimed.
Despite having taken some time to work through the case law and interpret the requirements imposed by section 43(2A)(b), the application of that law to the facts of ToolGen did not need to go beyond an application of the classical law on sufficiency (as found under s 40(2)(a)).
In ToolGen the priority document (P1) was “relatively short”[10], being “an unpublished journal article to which has been added an additional paragraph headed “Summary of the Invention”” that had been filed at the USPTO. As the reader will appreciate, academic publication is to report findings on what has been done and the consequences of those specific findings, they do not typically abstract from those findings some sense of a broader invention for establishing a priority right for a patent application!
P1 only disclosed a Streptococcus pyogenes CRISPR/Cas9 system and did “not identify any principle of general application which would permit the skilled addressee to determine whether any particular Type II Cas9 might reasonably be expected to work”[11] so as to justify the breadth of claims that extended beyond the specific bacterial system actually described and tested. The movement from that document to the later claim breadth would have required prolonged, non-routine research and experimentation, undertaken without meaningful guidance or assurance of success.
As Nicolas J stated “The disclosure required of P1 is that it be such as would enable the skilled team armed with the common general knowledge to make all, or substantially, all, embodiments within the scope of the claims without undue burden”.[12] Perhaps confusingly, the reader will recognize that explicit statement as being equivalent to the requirement under s40(2)(a), which Nicolas J had already dismissed as only partially satisfying the requirements that had been determined earlier in the decision.
When one is more than two – Miele
The development of the law described in ToolGen has been applied in a small number of decisions of the Federal Court after 2023 such as Miele in which Rofe J stated that (emphasis added):[13]
The invention in the claim of the complete specification must be disclosed in the priority document and must be also disclosed in a manner that is clear enough and complete enough for the invention in the claim to be performed by the person skilled in the art.
In that case, her Honour wrestled more with the threshold requirement for the earlier application to disclose the “same invention” (a hob assembly unit with one radial fan) as that which is later claimed before deciding that the requirement had not been met wither explicitly or implicitly (emphasis added):[14]
An implied disclosure of a one fan assembly unit achieved via a reverse-engineered close reading of the specification: by patching together stray phrases, particular cross-sections depicting unilateral vapour flow, and a counter example showing the advantage of two fans, in the absence of an express limitation, does not constitute a clear and unambiguous disclosure or a disclosure of the invention in a manner that is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art.
Having found that the earlier application did not disclose the same invention as was being later claimed, for completeness her Honour also found that the description in the complete specification did not provide a “clear enough and complete enough” disclosure of the claimed invention:[15]
more than routine trial and error would be required to develop a one fan configuration which would enable the invention to generate sufficient suction to downwardly remove cooking vapours as required by claim 1.
NOCO, No Dice
To this point in the story, the relatively recent developments in Australia on the law of priority entitlement have been addressed by decisions of single judges of the Federal Court.
The recent decision of the Full Court of the Federal Court of Australia in The NOCO Company v Brown and Watson International Pty Ltd[16] affirms those positions, but does so in a way that swings the pendulum further from the original language used by the law-makers when drafting the Raising the Bar reforms. It deprives the claimed invention of the benefit of the earliest priority date based solely on the lack of disclosure of the “same invention” in the earlier application, without considering the technical merits of whether there was a “clear enough and complete enough” disclosure at all.
At first instance, Moshinsky J summarized the legal principles from ToolGen and Miele as being:[17]
(a) it is necessary to determine both: (1) whether the invention in the claim is disclosed in the priority document; and (2) if so, whether it is clear enough and complete enough for it to be performed by the person skilled in the art: ToolGen at [181], [183], [193]; Miele at [300]-[301];
(b) it is not sufficient for the priority document to provide a starting point from which the person skilled in the art may transition from one invention to another by use of the common general knowledge; the mere fact that it would be obvious to the person skilled in the art to use the disclosure in the priority document to produce what is claimed is not enough to obtain priority if, properly characterised, the priority document and the claim are for different inventions: ToolGen at [193]; Miele at [304];
(c) the position under Australian law is not materially different from the UK law as explained in the English authorities to which Nicholas J referred (such as Icescape): ToolGen at [193].
On application to the facts, Moshinsky J held that the main claims in each of the divisional applications were not entitled to priority from the earlier PCT application filed in 2014 because it did not disclose the “same invention” that was later claimed.
Having considered the expert evidence, Moshinsky J considered the substance of the differences between the claims in the divisional applications and the description of the invention in the PCT application and concluded that:
- Claim 1 in the divisional applications referred to a “power switch” however the PCT application only disclosed a FET switch and apparently “The device works in different ways depending on the type of power switch. The power switch is closely connected to the safety features that the invention is designed to achieve”; and
- Claim 1 in the divisional applications referred to a “control system or circuit” that is configured (1) to detect presence of the depleted/discharged battery and (2) to detect polarity of the depleted/discharged battery, however the PCT application only disclosed the use of “two sensors” to detect those matters. It was found that “The device would work in different ways depending on whether, for example, one sensor is used or two sensors are used or some other system is used”.
On appeal, the Full Court affirmed Moshinsky J’s summary[18] but appeared to take an even stricter, more literal approach to whether the PCT application disclosed the “same invention”. In short thrift, the Full Court rejected the appellant’s submissions and in a single paragraph of consideration on each point accepted the positions taken by Moshinsky J, referring to the FET switch and two sensor features as being “consistently identified as essential throughout PCT 434, namely in the abstract, summary of the invention, detailed description, figures and claims”.
The brevity with which the Full Court resolved the question of priority entitlement, and the emphasis on the language in the earlier specification rather than expert evidence on any burden in expanding on that teaching, implies that the first limb (“same invention”) ironically encourages a mechanistic, perhaps even impoverished, approach.
Say It Early or Lose It Later
Read together, ToolGen, Miele, and NOCO leave Australian priority law with a threshold hurdle to overcome that is substantially aligned with Article 87 of the European Patents Convention which requires the earlier document to disclose the “same invention”.
Why are these developments significant? First since no application for special leave to appeal the decision to the High Court was filed, this decision now binds all lower courts and the decision makers at the Australian patent office. Second, the legal rationale enables a decision maker to deprive a claim of the benefit of an earlier priority date based purely on their construction of the language used in the earlier filing, without any consideration of whether it would be reasonable to extrapolate from that position without undue burden, as might be argued using expert evidence.
While I appreciate that the explanatory memorandum for our Raising the Bar reforms argued for increased harmony for our priority date provisions with “most other major patent jurisdictions”, I feel (with the greatest of respect) that the EW Court of Appeal’s approach in Unilin to rewriting the text of the UK Patents Act 1977 has indirectly encouraged our Courts to move away from our statutory language.
The practical lesson is straightforward. An earlier filing must disclose not just a working embodiment, or even a generalization of that embodiment – instead it must disclose the same invention the applicant may later want to claim. ToolGen shows the danger acutely in fast-moving technologies, where provisional drafting can lag behind inventive ambition. Miele and NOCO show the same risk in more mechanical contexts: if the specification stays tied to concrete embodiments and fails to abstract the inventive concept properly, priority may be lost.
[1] s 43(2A) of the Patents Act 1990 (Cth).
[2] Intellectual Property Laws Amendment (Raising the Bar) Bill 2011 [2012], Explanatory Memorandum, Item 10.
[3] Intellectual Property Laws Amendment (Raising the Bar) Bill 2011 [2012], Explanatory Memorandum, Item 8.
[4] Biogen Inc. v Medeva plc [1996] UKHL 18; [1997] RPC 1 at [70]; building upon Asahi Kasei Kogyo KK’s application [1991] RPC 485.
[5] ToolGen Incorporated v Fisher (No 2) [2023] FCA 794 at [166].
[6] ToolGen Incorporated v Fisher (No 2) [2023] FCA 794 at [182] to [183].
[7] Icescape Ltd v Ice-World International BV [2018] EWCA Civ 2219
[8] Unilin Beheer BV v Berry Floor NV & Ors [2004] EWCA Civ 1021 at [39].
[9] ToolGen Incorporated v Fisher (No 2) [2023] FCA 794 at [181] and [194] to [195].
[10] ToolGen Incorporated v Fisher (No 2) [2023] FCA 794 at [52].
[11] ToolGen Incorporated v Fisher (No 2) [2023] FCA 794 at [217] and [319].
[12] ToolGen Incorporated v Fisher (No 2) [2023] FCA 794 at [333].
[13] Miele & Cie KG v Bruckbauer [2025] FCA 537 at [301].
[14] Miele & Cie KG v Bruckbauer [2025] FCA 537 at [373] and [378].
[15] Miele & Cie KG v Bruckbauer [2025] FCA 537 at [458].
[16] [2025] FCA 887.
[17] The NOCO Company v Brown and Watson International Pty Ltd [2025] FCA 887.
[18] The NOCO Company v Brown and Watson International Pty Ltd [2025] FCA 887.
