An invitation to pay additional search fees is not automatically issued when lack of unity is found. If it is possible to complete the search and produce an ISO for both or all inventions with minimal additional search effort (that is, “negligible additional work” – see [PCT/GL/ISPE/12 at para 10.65]) then an invitation should not be issued.

As a guide, if the extra work entailed in searching for and examining an additional invention is estimated to entail “significant additional effort”, then an invitation should be issued.

Common circumstances in which a search / examination is likely to require “significant additional effort” include:

the different inventions require a search in different IPC sub-groups (or search areas) which are of significant size;
the different inventions, while requiring the search to be carried out in the same search area, are not sufficiently close in subject matter to avoid significant additional effort in searching them; and
the claiming structure (that is, the number of independent claims and the manner of appendance) is such as to require the expenditure of significant additional effort in examining them.

It may not always be necessary to request additional search fees when lack of unity is found a posteriori, such as when most of the search has already been done. However, where documentary evidence can be quickly located (for example, in the Australian search material) which establishes the lack of novelty, and it is otherwise justified in light of the above, an invitation to pay additional fees may be considered.

In some cases, it may require a modest or insignificant amount of additional effort to search one or more additional inventions in an application (that is, “negligible additional work” – see [PCT/GL/ISPE/12 at para 10.65]), but a search of all inventions in the application would place an undue burden upon the Office. In such cases it may be possible to group inventions together and request a separate fee for the search and examination of each group. However, lack of unity will be reported on in the ISR and ISO with respect to each invention, rather than each group of inventions.

Where it is considered that an invitation to pay additional search fees should be issued, the examiner will complete form PCT/ISA/206, and gain approval from their supervising examiner (following the procedures listed in the RIO for Patents Manual (Create Correspondence task)). The supervising examiner is the authorised officer for an invitation to pay and the time limit for a response to an invitation is one month. [Rule 40.1].

The invitation to pay additional search fees must be accompanied by a logically presented, technically reasoned statement of the basic considerations behind the finding of lack of unity. Other than in the circumstances referred to in 6.1.4.10 Unsupported, Unclear, Long and/or Complex Claim Sets with Clear Lack of Unity it is not sufficient to merely list the inventions contained in the application if the applicant cannot infer from this list alone that the inventions do not relate to a single inventive concept (see Heat Exchanger/SCHICK OJ EPO 2/1987, 63, and other subsequent decisions in the EPO). The applicant must be fully informed of the considerations that have led to the decision that there is lack of unity - see 6.1.4.14 Reported Decisions. [PCT/GL/ISPE/12 at para 10.74]

The explanation should also include the basis for the number of additional search fees invited and, where applicable, indicate which inventions can be searched with another without requiring a separate search fee. Examiners should note that the correct number of additional search fees is one less than the number of inventions, provided work entailed in searching for and examining each extra invention is estimated to be “significant additional effort”, as discussed above. The amount of search fees is as given in Schedule 7 part 3 of the Patents Regulations.

As a guide to the level of explanation required, the reason for lack of unity should be clear solely by reference to the relevant claims and the explanation. If lack of unity is raised a posteriori, the explanation must include reference to the relevant citation(s).

If the application contains claims that are directed to matter that the Australian Patent Office is not required to search, or that fail to comply with the prescribed requirements to the extent that a meaningful search cannot be carried out (see Article 17(2) and 6.1.6 Subjects to be Excluded from the Search, box 3 of the invitation to pay additional fees should be checked and the unsearchable claims noted.

If the examiner expects that search and examination of any of the inventions would be significantly restricted due to issues pertaining to Articles 5 and 6 (see 6.1.7.3 PCT Articles 5 and 6, such matters may briefly be explained in the invitation to pay additional fees.

All claims relying on references to the description or drawings (in particular, omnibus claims), except in those cases where it is absolutely necessary, will fail to meet the requirements of Rule 6.2(a). Hence, no search or opinion is to be established for these claims. This circumstance is required to be mentioned on the form PCT/ISA/206 by:

checking Box 3 and indicating which claims have been found to be unsearchable; and
inserting the text “The claims do not comply with Rule 6.2(a) because they rely on references to the description and/or drawings.” directly below.

Annex E illustrates the level of detail required.

Paragraphs 10.21 - 10.59D of the PCT International Search and Preliminary Examination Guidelines shows examples concerning unity of invention.

Generally, having issued the invitation to pay additional search fees, the search is to be conducted (or continued) in respect of the invention first mentioned in the claims. [Article 17(3)(a)].

However, where under the procedure of 6.1.4.10 Unsupported, Unclear, Long and/or Complex Claim Sets with Clear Lack of Unity, the applicant has asked that an invention other than the first mentioned invention be searched, the search may proceed on that basis. Searches of any other identified inventions should not proceed until an additional fee or fees have been paid.

In all cases the search report must clearly indicate the parts of the application that were and were not searched.

Note that the guidelines in para 10.61 of the PCT International Search and Preliminary Examination Guidelines suggest that the invitation to pay additional search fees be accompanied by a partial search report in relation to the invention first mentioned in the claims. This is not current Office practice.

If additional fees are paid in respect of one or more of the further inventions the additional searches and examinations are to be arranged and completed as soon as possible. Where the additional fee or fees are paid outside the time provided for in the invitation, the case is to be referred to the Supervising Examiner for consideration of the applicability of Article 48 of the PCT or the appropriateness of resetting the time allowed in the invitation, before any additional searches and examinations are commenced. Subject to this, an additional search and examination is to be conducted only if the fees are paid within the time allowed; fees paid outside this time are refunded (Fuel Products/LUBRIZOL OJ EPO 5/1988, 182).

If an invitation to pay additional search fees is issued, RIO will automatically update the CSC due date to reflect 12 weeks from receipt of the search copy by the ISA.

If the situation arises where an application includes more than one invention and at least one of the inventions is covered by an earlier search a refund may be applicable as per the processes in Annex S. However an additional search fee for the invention(s) not covered by the earlier search may be required. If it is determined that additional searching is required for the other invention(s), examiners are required to issue the ITP as per the normal circumstances to cover the additional search effort required. Once the ITP process has been followed and the search report and opinion have been completed, a refund should be considered as per the normal process for the invention(s) covered by the earlier search.

Amended Reasons

Amended Reason	Date Amended
	18 Oct 2023
Published for testing	06 Jun 2023