A sure footing confirmed for obvious mistakes in patent specifications

A recent decision[1] of the Federal Court has confirmed the requirements for amending a patent specification to rectify a clerical error or obvious mistake and provided a timely reminder of the importance of reviewing a patent before commencing proceedings.

The amendment application was made during proceedings commenced by Surefoot IP Holdings Pty Ltd (Surefoot) against All Footings Solutions Pty Ltd (All Footings) for infringement of its patent to “Improved footing plates”.

Surefoot sought orders pursuant to s 105(1) of the Patents Act (the Act) to amend claim 2 of the Patent to correct a clerical error, and in particular to correct the word “sited” in claim 2 to read “sized” as set out below:

A footing plate including a planar web from which a plurality of tubes originate and descend, said tubes being adjacent the edges of the planar web and being disposed at angles to the planar web, none of said angles being 90˚, said tubes being sited sized to permit the passage therethrough of pins for fixing thereof into underlying ground, the planar web being provided with a downwardly extending flange on at least one of the edges of the planar web.

All Footings initially opposed the amendment but withdrew its opposition before hearing and the application was dealt with by Justice Rofe on the papers.

The decision confirms the principles applying to an amendment to correct a clerical error or obvious mistake under s 102(3) of the Act, relevantly that:

  • the onus to establish that the error is a clerical error or an obvious mistake lies with the patentee seeking the amendment;
  • a clerical error occurs where a person, either of his own volition or under the instructions of another, intends to write something and by inadvertence either omits to write it, or writes something different;
  • the characteristic of a clerical error is not that it is in itself trivial or unimportant, but that it arises in the mechanical process of writing or transcribing:
  • an obvious mistake is one that the instructed public can, from an examination of the specification, appreciate the existence of the mistake and the proper answer by way of correction;
  • it is not enough for an obvious mistake if merely the presence of a mistake is obvious if one cannot appreciate the correct answer; and
  • it does not matter that the claim may be enlarged by the amendment.

Surefoot’s evidence was that its Director, patent attorney and legal advisers were all unaware of the error before noticing it in the course of preparing Surefoot’s position statement on infringement, and that the error likely arose between the filing of the Provisional (which used the word “sized”) and the international application.

The evidence described in significant detail, the steps from preparation of the provisional to Surefoot’s patent attorney becoming aware of the error but did not provide any real explanation of how the error occurred, or how it was overlooked for so long.

Ultimately, Justice Rofe held that the evidence did not satisfy the requirements of a clerical error, although her Honour did consider the error to be an obvious mistake – the existence of the mistake and the proper answer by way of correction could be appreciated from an examination of the Patent.

Notably, the fact that many trained minds reviewed the specification in the course of prosecution, and that the error was not noticed until August 2021, was not fatal to a conclusion that it was an obvious mistake.

Despite the proposed amendment meeting the requirements of s 102, the Court still has a broad discretion under s 105 as to whether or not to allow an amendment in order to ensure an amendment application is made promptly, for proper purposes, and does not allow the patentee to obtain an unfair advantage.

In this case, the court was satisfied that the amendment should be allowed, noting that Surefoot had moved promptly to correct the error, and had not gained any real advantage in commencing proceedings on the unamended patent.

Although Surefoot was able to successfully amend the specification, there are countless scenarios where such an amendment would provide an advantage to the patentee and/or be relevant to the question of infringement or validity. This decision provides yet another reminder to patentees that it is crucial to properly review claims before commencing proceedings.


[1] Surefoot IP Holdings Pty Ltd v All Footings Solutions Pty Ltd [2022] FCA 119



David is an experienced IP litigator and registered patent and trade marks attorney who brings a technological understanding together with legal expertise to resolve IP disputes for Australian and international businesses.