PA 03/2009: Payment of additional preliminary examination fees in case of earlier finding of lack of unity of invention by the International Searching Authority

WARNING: Although the information which follows was correct at the time of original publication in the PCT Newsletter, some information may no longer be applicable; for example, amendments may have been made to the PCT Regulations and Administrative Instructions, as well as to PCT Forms, since the PCT Newsletter concerned was published; changes to certain fees and references to certain publications may no longer be valid. Wherever there is a reference to a PCT Rule, please check carefully whether the Rule in force at the date of publication of the advice has since been amended.

Q:  The International Searching Authority (ISA) considered that an international application for which I am acting as agent did not comply with the requirement of unity of invention as it contained two separate inventions, and invited me to pay an additional search fee to cover the cost of carrying out a search in respect of the second invention.  I therefore paid the additional fee and had all the claims searched.  In view of the above, do I automatically have to pay an additional preliminary examination fee to the International Preliminary Examining Authority (IPEA) if I decide to file a demand for international preliminary examination?

A:  It is recalled that, according to PCT Rule 13.1, the international application must relate to one invention only or to a group of inventions so linked as to form a single general inventive concept (“requirement of unity of invention”).  Where the ISA finds lack of unity of invention, the IPEA may also find lack of unity of invention, especially if the IPEA is the same Office as the ISA. 

Even though it is likely, therefore, that the IPEA will also invite you, in accordance with PCT Rule 68.2, to pay an additional fee for the second invention in the context of international preliminary examination (or otherwise, to restrict the claims), there is a chance, especially if the IPEA is not the same Office as the ISA, that the IPEA may come to a different conclusion concerning the lack of unity, and may not require payment of additional fees.  You therefore do not need to automatically pay the additional preliminary examination fee, as the IPEA may not necessarily invite you to pay that fee. 

Another reason why you need not pay that fee automatically is that, under PCT Rule 68.1, the examiner has the option of examining any further inventions without inviting restriction of the claims or payment of additional fees where, for example, compared with the procedure of inviting the applicant, no or little additional effort is involved in establishing the international preliminary report on patentability (Chapter II of the Patent Cooperation Treaty) (hereinafter:  report) for the entire application.  The examiner may draw this conclusion in view of the fact that the majority of the work in creating a written opinion on the additional inventions will have been done by the search examiner, and the Chapter II examiner will in any case have already reviewed at least the independent claims in order to confirm the view on unity of invention.  Whether or not the examiner invites payment of additional fees may also depend on the extent and complexity of any amendments which need to be taken into account for the international preliminary examination. Where the examiner proceeds with the preliminary examination without requesting any additional fees, he establishes the report on the entire international application, but indicates in the report his opinion that the requirement of unity of invention is not fulfilled and the reasons therefor.

In any case, if the IPEA is not prepared to examine all claims of the application without the payment of additional fees, it will invite you under PCT Rule 68.2, by way of Form PCT/IPEA/405, to either restrict the claims or pay such fees before establishing the report.  If you fail to take either of these two actions, the report will only cover the first invention.

Therefore, in the case you describe, you may wish to wait and see whether you are going to be invited to pay additional fees also during international preliminary examination, or, as a practical matter, to save time you may wish to raise the matter with the IPEA examiner at the time of filing the demand.  As stated above, whether or not you will be invited to pay an additional fee will be closely linked to whether or not the IPEA is the same as the ISA, and/or to the scope of amendments made when filing the demand for preliminary examination.

For further information, see paragraph 10.76 of the International Search and Examination Guidelines at:

the PCT Applicant’s Guide, International Phase, paragraph 398 at:

and the “Practical Advice” in PCT Newsletter Nos. 08 and 09/2008.


References: r_13_pct; r_68_pct;

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