Welcome to the new version of the Patents Manual. Please note there are changes to the numbering and sequence of the chapters and pages in the manual. You are encouraged to take the time to explore and familiarise yourself with this new structure. Response to Opinion

Date Published

Also in this Chapter:​​​​​​​

Key Legislation:

Regulations under the PCT:

  • Rule 6.2 References to Other Parts of the International Application
  • Rule 66.2 Written Opinion of the International Preliminary Examining Authority
  • Rule 66.4 Additional Opportunity for Submitting Amendments or Arguments
  • Rule 66.4bis Consideration of Amendments, Arguments and Rectifications of Obvious Mistakes
  • Rule 66.5 Amendment
  • Rule 66.6 Informal Communications with the Applicant
  • Rule 66.8 Form of Amendments

PCT ISPE Guidelines:

  • para 19.31 Further Stage of International Preliminary Examination
  • para 19.34-19.35 Correction of International Preliminary Examination Report
  • para 20.04 Making Amendments: General Considerations

If there is no response to an Opinion and there is less than one month remaining to establish the IPRPII examiners should establish the report as in 6.3.7 IPRPII and Notification Rule 66.4bis. The PCT Unit will forward these files to the section which issued the opinion when less than one month remains.

Where a response is received in the form of arguments only, reconsider the IPEO in the light of those arguments. [Rule 66.4(b) PCT/GL/ISPE/12 at para 19.31 et seq]

Where a response is received which includes amendments (Rule 66.5 - "Any change, other than....... obvious mistake,....... shall be considered an amendment"), consider the amended description, drawings, and/or claims as in General Notes on Form Completion [PCT/GL/ISPE/12 at para 20.04 et seq]

Where a response is received after the PCT Unit has forwarded the file to an examination section to establish the report, but the report has not yet been established, then that response may be considered if it is reasonable to do so.  In this regard, note Rule 66.4bis (amendments or arguments need not be taken into account).

Where a response which includes amendments, but does not include the letter referred to in the second sentence of Rule 66.8(a) (explaining the differences between the replaced sheets and the replacement sheets) then, unless the presence of this letter is critical to the understanding of the amendments, its absence should not interrupt processing and the response should receive immediate detailed consideration. Where, because of exceptional circumstances, the letter is required, and time permits, then a request for this letter may be despatched using the form PCT/IPEA/424 (see RIO for Patents Manual (Create Correspondence Task)).

In order to determine whether an opinion should be issued or the IPRPII should be established in light of an applicant’s response, the examiner must consider both the nature of any outstanding issues and the time remaining before the final date for establishing the IPRPII.

If there are still Rule 66.2 matters (general international preliminary examination considerations) which apply, then the examiner should issue another opinion provided there is sufficient time remaining to do so.  As a general rule, if there is more than 3 months to go until the final date for establishing the IPRPII, then this is considered to be sufficient time for the applicant to make a further response and for the examiner to properly consider that response.  If less than 3 months remains, either the IPRPII should be established – or, if the circumstances favour it, the examiner may make informal communication with the applicant – see Extensions of Time to Respond to Opinions.

If, after consideration of an applicant’s response, there are no outstanding issues or the only outstanding issue relates to Rule 6.2(a) matters (omnibus claims), the examiner should establish the IPRPII regardless of any timing considerations.


  1. The time limit set in this new opinion should be one month.
  2. Where an informal communication is made with the applicant (Rule 66.6 - informal communication with applicant) it should be formalised by a subsequent despatch summarising the content and results of such a communication. Forms PCT/IPEA/428 and PCT/IPEA/429 are available from the PCT Unit.

There is no barrier to resuming international preliminary examination after an IPRPII has been issued, provided the circumstances justify such an action. Any replacement report resulting from the re-opening of international preliminary examination should be clearly labelled as such so that elected offices are aware of its status. [PCT/GL/ISPE/12 at para 19.34, 19.35].

The PCT Unit will advise WIPO to disregard the earlier report. If the resulting response is a further IPEO, then this opinion will be sent to the applicant only. However, when the resulting response is another IPRPII, this will be sent to both the applicant and WIPO as a "corrected version" of the IPRPII.

The type of circumstance prima facie justifying the re-opening of international preliminary examination is where the IPRPII was issued earlier than it otherwise would have, by reason of an error or omission on the part of either the Commissioner, applicant or attorney. For example, where it had been the intention of the applicant to respond but as a result of an omission by the applicant's attorney no response had been made.  Where examiners become aware of circumstances that prima facie justify the resumption of international preliminary examination after an IPRPII has been issued, they should bring the matter to the attention of their Supervising Examiner who should then consult with OEP.

Note:  Once examination of a particular application has been re-opened, any subsequent request to re-open examination of that application should not be entertained.

Amended Reasons

Amended Reason Date Amended

Published for testing

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