Unity of Invention Background

Date Published

Where the ISA considers that the international application does not comply with the requirement of unity of invention, it may invite the applicant to pay additional search fees in order that inventions other than the first mentioned invention in the claims may be searched. [Article 17(3)(a) PCT/GL/ISPE/8 Chapter 10]

Unity of invention must be considered at the earliest possible opportunity.  The consequences of this step are considerable due to the large cost and time associated with PCT searching as well as the time limit imposed by the PCT for completion of the search report.  If it is not clear that the claims lack unity after considering the issue for a minimal period of time, such as 15 minutes, then it will generally be more efficient for the search to proceed on the basis that there is no lack of unity.  Further time spent conclusively determining whether or not there is lack of unity is likely to be counter-productive.  However, if lack of unity is not raised in appropriate circumstances, an unnecessary cost is imposed on the Office if significant additional searching effort results.  Also, if lack of unity is raised when it should not have been, there may be insufficient time later to complete the required search; and if the issue is raised incorrectly the Office may not be able to abide by the original finding of lack of unity and be required to refund any extra fees paid.

Lack of unity must be determined solely from the language of the claims (as properly construed) and, where appropriate, by having regard to relevant prior art.  In particular, the size of the search required or the number or nature of classification areas that need to be searched is not relevant to the determination of lack of unity; this is only relevant to whether an invitation to pay extra fees should be issued once lack of unity has been established.  If a large search is required, careful attention should be given to the search strategy adopted (see 4.1 Searching).