PA 05/2019: Possible implications of submitting informal drawings when filing the international application

WARNING: Although the information which follows was correct at the time of publication, 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:  I filed a national patent application ten months ago, and would now like to file a PCT application, claiming priority of the earlier application.  As the drawings that I filed with the earlier application were very informal, I wondered whether I should file the international application now with the drawings as they are, and then submit formal drawings later, once they have been prepared, or whether I should wait until the drawings have been prepared before filing the PCT application?  I am worried that the informal drawings are so bad that they might be perceived as being substantially different from the formal drawings.

A:  Although some national or regional Offices may be prepared to accept more informal drawings in accordance with their own national or regional practice, and may accept replacement formal drawings later on without any problems, please be aware that, as far as the PCT procedure is concerned, it is strongly recommended to submit formal drawings at the time of filing the international application. 

Some of the drawbacks and potential risks that you may encounter if you do not submit formal drawings at the time of filing the international application are considered below.

One potential problem with submitting replacement drawings to the receiving Office (RO) after filing the international application is that, depending on the nature of the improvements to the drawings, the new drawings might appear, from a formal perspective, substantially different from the originally‑filed drawings and the formalities examiner may, in such a situation, be reluctant to accept the former for fear that they might add new material to the application;  it may therefore not be possible to correct the drawings under PCT Rule 26.  You should be aware that formalities examiners at ROs or at the International Bureau (IB) are trained to examine the application as to form;  they are not necessarily technically trained in the field relating to the subject matter of the international application.  It is only when the RO transmits the application to the International Searching Authority (ISA) for the purposes of international search that it will be looked at by someone who is technically trained in the relevant scientific or engineering discipline, and who would be in a position to evaluate whether a new drawing includes new matter or not.

If the drawings cannot be corrected under PCT Rule 26 due to the difference(s) between the drawings as filed and the replacement drawings, there may be the possibility to request the rectification of an “obvious mistake” under PCT Rule 91 before the ISA.  However, the requirement under PCT Rule 91.1(c) that it would have to be obvious to the ISA that, as at the international filing date, “something else was intended than what appears in the document concerned and that nothing else could have been intended than the proposed rectification” would most likely be difficult to meet. 

If (replacement) formal drawings are not accepted for the purposes of the international procedure, the examiners during the international search procedure, and, if applicable, the international preliminary examination procedure, may experience problems if the quality of the informal drawings is very poor – it may slow down their work and affect the quality of the search/examination.  Furthermore, the IB would publish the international application with the informal drawings as filed, rather than the formal ones, and the designated (or elected) Offices would have access to the informal drawings upon entry into the national/regional phase. 

One option that you could consider, if you do not have your formal drawings accepted before international publication, is to file a demand for international preliminary examination, accompanied by amendments to the drawings under PCT Article 34(2)(b).  Such amendments do not need to satisfy the “nothing else could have been intended” requirement of PCT Rule 91.1(c).  Furthermore, as is the case with the ISA, the International Preliminary Examining Authority (IPEA) has technically trained staff in the relevant scientific or engineering discipline, and would be in a position to evaluate whether a new drawing includes new matter or not.  If the IPEA concludes that no new matter has been added (and that other procedural requirements have been met), it will include the formal drawings as an Annex to the International Preliminary Examination Report.  Although the amended drawings included in that Annex would not form part of the international publication (the informal drawings would still be published as part of the international application), they would be available on PATENTSCOPE, and available to the designated (or elected) Offices, but not before the expiration of 30 months from the priority date (PCT Rule 73.2(a)).  You should, however, bear in mind that, as mentioned above, extra fees would be payable under the international preliminary examination procedure, and that waiting to find out whether the drawings have been accepted by the IPEA may prolong the uncertainty.

If you do not amend the drawings in the international phase under PCT Article 34, the designated (or elected) Offices (DOs/EOs) would, at the point of entry into the national or regional phase, use the drawings as published.  You would, however, be entitled to submit amended drawings to the DOs/EOs under PCT Rule 52 or 78, which would be taken into account when determining whether or not to grant a patent (or other form of protection, if applicable) if they are received within the applicable time limit.  Note that if you submit amendments to each DO/EO before which you wish to enter the national or regional phase, this would normally be more costly than either making the amendments before filing, or making them during the international phase.

It is recalled that all drawings submitted as part of an international application must comply with the PCT standard for drawings contained in PCT Rule 11.10 to 11.13.  Further information on the formality requirements for drawings is also available in paragraphs 5.131 to 5.160 of the PCT Applicant’s Guide at:

If the RO finds that the submitted drawings do not comply with PCT requirements, it will invite the applicant (using Form PCT/RO/106) to correct any defects within a time limit set in the invitation (or within an extended time limit, if granted by the RO, provided that the corrected drawings reach the IB before the technical preparations for publication have been completed).  If an applicant fails to correct defects in drawings, and the RO finds that, in accordance with PCT Rule 26.5, the international application does not meet the physical requirements of PCT Rule 11, the RO could in theory consider the international application withdrawn.  It is, however, rare for an RO to consider an application withdrawn because of defects in the drawings;  applicants are, in effect, protected somewhat by the proviso under PCT Rule 26.5 whereby no international application will be considered withdrawn for lack of compliance with the physical requirements referred to in PCT Rule 11 if it complies with those requirements to the extent necessary for the purposes of reasonably uniform international publication.   

To conclude about your specific case – although it is preferable to include formal drawings in the international application as filed, if you do not have time to prepare formal drawings before you file the international application, it may be safer to file the application with informal drawings (and try and replace them later with formal drawings), rather than to miss filing the application within the 12‑month priority period. 

You may also find it useful to read the following Practical Advice articles concerning drawings and compliance with physical requirements:

It is recalled that ePCT has a dedicated preview function1, which enables applicants to view, pre‑filing, and without having to log in, any drawings provided in either PDF or DOCX format as they will be rendered by the IB for subsequent processing and publication.  Information on this useful function was published in the Practical Advice in PCT Newsletter No. 04/2019 at:

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