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2.1.6.2.4 Lack of Unity

Date Published

This section is directed to the level of detail required when taking a lack of unity objection. Direction on the basis of lack of unity objections is provided at 2.11.8 Claims Relate to One Invention Only – Lack of Unity. Considerations for the use of FERs and reserving search and examination is given at:

An objection that the claim or claims of a complete specification do not "relate to one invention only" should only be taken where there are claimed inventions that are clearly not so linked as to form a single inventive concept.  The objection is applicable only when more than one invention is claimed. It is not relevant for the purposes of sec 40 that the complete specification describes, but does not claim, more than one invention.  Examiners are expected to exercise their judgement and take a pragmatic approach when deciding how to proceed in view of a lack of unity.  

The report should include a fully reasoned explanation of the consideration behind the finding of lack of unity - it is not sufficient to merely list the different inventions claimed. For example, if lack of unity is raised a posteriori, the explanation must include reference to the relevant citations. The level of detail required is shown in 1.1.19 Annex E – Completed Invitation to Pay Additional Fees.


Note: Where a claim contains embodiments directed to different identified inventions, the lack of unity objection should reflect this, for example:


Invention 1. Claims 1-20 and 21 (in part) relate to compounds of formula 1, a process for their preparation, pharmaceutical compositions containing them and methods for their use as antibiotics.


Invention 2. Claims 21 (in part) and 22-29 relate to compounds of formula 2, pharmaceutical compositions containing them and methods for their use as anti-inflammatories.


In some cases, where inventions are closely related, even though there is a technical lack of unity, it will require only negligible additional effort to carry out examination on the additional inventions. This may occur where, for example, the prior art to be considered for each invention is similar, or where earlier search results or FERs are available and at least some of the additional inventions have been searched or examined. In assessing whether or not the effort required to examine the additional invention(s) is “negligible”, examiners should have regard to the time likely to be required to draft and perform any additional search, consider documents found, assess any other issues (e.g. sec 40) relating to the claims in question and the estimated time to complete any further reports.  This is to be weighed against the time required to formulate and maintain as appropriate the corresponding objection to lack of unity.

Having weighed these factors, where expeditious to do so, examination is to be carried out in relation to those inventions that can be accommodated with negligible additional effort.

Where there is lack of unity and the examiner becomes aware of prior art related to inventions upon which examination is not being carried out (whether or not as a result of a "partial" search or examination), this information may be included in the report, depending on its level of relevance. (Refer to 4.1.4.2.4 Reserving the Search for discussion of the issues associated with conducting a partial search and the citation of documents arising from such a search).



Reserving Opinion

Where, as a result of a lack of unity objection, only certain inventions are examined, this must be clearly indicated in the report, together with a statement that opinion in respect of those inventions not examined is reserved.

Furthermore, where a claim encompasses embodiments directed to more than one of the identified inventions and opinion has been reserved in respect of at least one of these, the lack of unity objection should indicate that part of the claim concerned has been examined, while part has been reserved.  For example:

“I have limited the search and report to Invention 1 as defined by Claims 1-20, 21 (in part).

When I receive a response to my objections I may extend the search area and expand the report on the basis of my findings.”


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