6.1.4.1 Unity of Invention Background

Also in this Chapter:

• 6.1.4.2 Determining Lack of Unity

• 6.1.4.3 Combinations of Different Categories of Claims

• 6.1.4.4 Markush Practice

• 6.1.4.5 Intermediate and Final Products in Chemical Applications

• 6.1.4.6 Biotechnological Inventions

• 6.1.4.7 Single General Inventive Concept

• 6.1.4.8 A Priori and A Posteriori Lack of Unity

• 6.1.4.9 Issuing the Invitation to Pay Additional Search Fees

• 6.1.4.10 Unsupported, Unclear, Long and/or Complex Claim Sets with Clear Lack of Unity

• 6.1.4.11 Payment of Additional Search Fees Under Protest

• 6.1.4.12 Completing the Search Report

• 6.1.4.13 Time for Completing the Search Report

• 6.1.4.14 Reported Decisions on Unity

• 6.1.4.15 Other Decisions from the EPO

Key Legislation:​​​​​​​

PCT ISPE Guidelines:

• Chapter 10 Unity of Invention

Patent Cooperation Treaty:

• Article 17(3)(a) Procedure Before the International Searching Authority 

Related Chapters:

• 4 Searching

On this page

• Overview

• Unity of invention considerations

• Consequences of unity considerations

Overview

The International Search Authority (ISA) may invite the applicant to pay additional search fees where the ISA considers that the international application does not comply with the requirement of unity of invention. This is so that inventions other than the first mentioned invention in the claims may be searched. See Article 17(3)(a) and PCT/GL/ISPE/12 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

• the time limit imposed by the PCT for completion of the search report.  

Unity of invention considerations

If after considering the issue for a minimal period of time – such as 15 minutes – it is not clear that the claims lack unity, 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 counterproductive. 

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 Volume 4 Searching).

Consequences of unity considerations

If lack of unity is not raised in appropriate circumstances, an unnecessary cost is imposed on the Office if significant additional searching effort results. 

If lack of unity is raised when it should not have been, there may be insufficient time later to complete the required search. Additionally, 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.