Welcome to the new version of the Patents Manual. Please note there are changes to the numbering and sequence of the chapters and pages in the manual. You are encouraged to take the time to explore and familiarise yourself with this new structure. General Principles

Date Published

Key Legislation:

Patents Act:

  • s18 Patentable Inventions
  • s40 Specifications 

Related Chapters:

  • 2.11.2 Construction of Specifications
  • What is the Invention?


The requirement that the claims be fairly based on the description is a requirement of consistency of the claims with the description or, more particularly, with the invention described.

As noted by the High Court in Kimberly-Clark v Arico (paragraph 12), the general principle underlying fair basis is:

‘... where the issue is one under s40(3) of "fair basing" of a claim, what the 1990 Act requires is a comparison between the matter described in the specification and the claim which defines the scope of the monopoly.’

In order for a claim to be fairly based, the claims must be consistent with what the specification as a whole describes as the invention.  As a consequence, fair basis does not require any evaluation of whether the breadth of the claims exceeds "the technical contribution to the art embodied in the invention". It also does not entail any consideration of whether it is a "patentable invention" under any of the criteria of s18, nor any inquiry into "inventive step" or inventive "merit".

Consequently, the test to be followed for fair basis is:

  • Having regard to the specification and claims, identify the invention which is described and around which a particular claim is drawn;

  • Compare the claim with that invention – as described in the body of the description; and

  • Assess whether the claims are consistent with the invention described in the specification, i.e. whether there is a “real and reasonably clear disclosure” of the invention as defined by the features of the claim or whether the claims “travel beyond the subject matter of the invention”.

Applying the Test

The critical analysis for fair basis is to ensure that the specification is construed properly to determine what the specification as a whole considers the invention. Having done this, the step of comparing the invention with the claims to ensure consistency for the purposes of fair basis is straight forward (see 2.11.2 Construction of Specifications and particularly What is the Invention?)

Having determined the invention described in the specification “as a whole”, examiners should then consider the claims to determine whether they are consistent with the described invention or whether they “travel beyond the subject matter of the invention described”.

Where the invention as claimed is inconsistent with some elements of the description, it is appropriate to raise an objection of lack of fair basis. Once a response has been received, examiners will be able to determine whether the benefit of the doubt should be given to the applicant.

Note that a consistory statement on its own is not sufficient to provide fair basis (see the discussion of Lockwood below).


1.  Atlantis v Schindler (1997) 39 IPR 29

The title of the specification is “Drainage Cell”. The specification describes a shortcoming in known methods of draining and describes a new device for use as a drainage cell. The Court held that the invention disclosed in the specification was a drainage method (or use of the drainage cell) and not the drainage cell per se, despite some conflicting statements to the contrary. Claims directed to the drainage cell per se were thus not fairly based.

This case illustrates the importance of construing the specification carefully. Even though the drainage cell per se was described in the specification, the emphasis of the description was to the use of the drainage cell for drainage. Consequently, there was only fair basis for the use of the drainage cell.

2.  Lockwood v Doric (2004) 217 CLR 274

Latch assemblies commonly have features (i)-(v). The consistory statement refers to locks with the additional feature (vi) of an outside actuator that renders the locking means inactive. The Court held that the consistory clause was supported by those parts of the specification describing features that "generally" or "preferably" existed and which, while explaining the invention in detail by reference to the drawings, stressed that they are merely illustrative of how the invention might be put into effect and were not exhaustive. Hence claim 1 in similar terms to the consistory statement was fairly based.

It is important to note that the consistory statement on its own did not provide fair basis for the claim. However, as the consistory statement was supported by the rest of the description, there was fair basis in the specification as a whole.

3.  PhotoCure v Queen’s University (2005) 64 IPR 314

The patent relates to treatment of skin disorders. The consistory statement refers to a wide range of skin disorders, but the examples are limited to 5 disorders and other uses are only “contemplated”. The Court held that the detailed explanation of the further uses indicated that the treatment was directed more broadly than the 5 examples, and provided fair basis for the wide range of disorders.

This case demonstrates the danger of focussing on one part of the specification alone (in this case the examples).

Amended Reasons

Amended Reason Date Amended
Back to top