PA 03/2019: Filing strategies:  factors to consider when deciding whether to file an international application with a national (or, where applicable, regional) Office or the International Bureau as receiving Office – an example of a US resident [..]

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.

Filing strategies:  factors to consider when deciding whether to file an international application with a national (or, where applicable, regional) Office or the International Bureau as receiving Office – an example of a US resident who is a national of Canada

Q:  I am a US patent agent and have been approached by a client who is resident in the US and a national of Canada.  The invention that my client wishes to protect was the subject of an earlier national filing in the US.  My client intends to file a PCT application and possibly sell the rights to it in the future.  As there may be a new applicant from an Asian country during the international phase, what factors do I need to take into account when deciding which receiving Office to file the application with?

A:  In accordance with PCT Rule 19.1, the international application should be filed with the national Office of the Contracting State of which the applicant is a national and/or resident, or with the International Bureau as receiving Office (RO/IB). 

Because of the nationality and residence of your client (hereinafter “the applicant”), he/she has the option of filing the PCT application with the receiving Offices (ROs) of the United States of America (RO/US), Canada (RO/CA) or RO/IB. 

Several factors may affect an applicant’s choice of RO, including:

  • national security considerations;
  • agent’s right to practice before the RO;
  • choice of International Searching Authorities (ISAs) and International Preliminary Examining Authorities (IPEAs);
  • language(s) accepted by the RO;
  • whether electronic filing is possible with the RO;
  • whether the RO has any outstanding notifications of incompatibility in relation to certain safeguard provisions (such as restoration of the right of priority under PCT Rule 26bis.3);
  • in the event of filing close to the expiration of the 12‑month priority period, the time zone difference and the hours of operation of the RO; and
  • cost of filing at the Office concerned (the transmittal fee and certain other fees which may have to be paid for the benefit of the RO vary amongst Offices) and whether the RO offers any fee reductions, as well as modalities of payment of fees.

We will look at some of the specific points that you may wish to consider when deciding with which RO to file the application, given the circumstances outlined in your question.  Note that these are not exhaustive, and there may be other issues to consider.

National security considerations

In most cases, you are considered to have permission to file with another Office if you have either filed an application for the same invention at the relevant national Office a certain amount of time previously (which varies from Office to Office) and have not received a security notice stating that you should not file elsewhere, or if you have explicitly requested and been granted permission.  Note that the United States law includes restrictions on the filing of patent applications for inventions made in the country.  Known national legislation which restricts the filing of international applications with other Offices for reasons of national security are summarized at:

Filing with RO/US:  Where the subject matter of the international application is identical to that of the earlier application, the priority of which is claimed in the international application, and the international application is filed with the same Office as the earlier application, any necessary security checks will normally already have been carried out by the time you file the international application.  If this is not the case, RO/US will not forward the application to the IB for processing (nor to the ISA for the purposes of international search) until such time as the national security clearance has been given. 

Filing with RO/CA or RO/IB:  if you file directly with either RO/IB or RO/CA, neither of these Offices will carry out a check of national security prescriptions – you would be responsible for ensuring that the PCT application complies with any U.S. national security requirements before filing.

Choice of ISAs and IPEAs

It could be useful, where possible, to choose an ISA which would search prior art that is particularly relevant to the region where protection is ultimately sought.  For example, if protection will be sought in Japan, it may be useful to choose ISA/JP as that Office may find relevant prior art in Japanese, which may not be accessible to other ISAs for language reasons.  Please also bear in mind that if you obtain positive search/examination results from an ISA (or IPEA) which is the same Office from which you ultimately wish to obtain a patent, this should make it easier to obtain positive results before that Office upon national examination.  However, choice of ISA (or IPEA) is limited, depending on the RO with which you file your international application.

RO/US:  you would have a wide choice of ISAs (and IPEAs) as RO/US has specified the following ISAs (and IPEAs):  the patent Offices of Australia (AU), Israel (IL), Japan (JP), the Republic of Korea (KR), the Russian Federation (RU), Singapore (SG) and U.S., and the European Patent Office (EP).  

RO/CA:  the Office has specified only itself as ISA (or IPEA), so you would not be able to choose any other Office as ISA (or IPEA) if you file with it. 

RO/IB:  the competent ISAs (or IPEAs) are the same as would have been competent if the international application had been filed with the national Office of, or acting for, a Contracting State of which the applicant is a resident or national (see PCT Rules 35.3 and 59.1(b)).  This means that applicants with different countries of residence and nationality filing an international application with RO/IB may have a wider choice of competent ISAs when compared with filing before a national (or where applicable, regional) Office acting as RO.  For instance, in your case, when selecting the ISA, you would be able to expand the ISA/IPEA coverage as you would be able to choose the Offices which have been specified to act as ISA (or IPEA) by RO/US (in view of the applicant’s country of residence) as well as by RO/CA (in view of the applicant’s nationality).  

It is recalled that you can request a supplementary international search by any of the Authorities that offer this service, regardless of the receiving Office with which you file the international application, but the Authority specified for supplementary international search must be different from the Authority that has performed the international search.

Right to practice before the RO

Although none of the three ROs require the applicant to appoint an agent, if an agent is appointed, there are certain requirements which must be met.

RO/US:  provided that you are registered to practice with the USPTO, you are entitled to act as an agent for the international application if you file with RO/US.  

RO/CA:  the agent must be a person or firm entitled to practice before the Office.  If you are not entitled to act before RO/CA, and the applicant wishes to be represented by an agent before that Office, he/she would have to appoint another agent who meets that requirement.  Otherwise, you could be included as an address for correspondence, however, any submission to the RO or the International Authorities would have to be signed by the applicant. 

RO/IB:  while any resident or national of a PCT Contracting State may file an international application directly with RO/IB (PCT Rule 19.1(a)(iii)), and the RO/IB is in that sense considered a “universal RO”, it is not the case that any agent could act as agent before the RO/IB – the right to practice is governed by PCT Rule 83.1bis1 and the question of which agent may act as such for a particular international application is linked to the nationality and residence of all applicants.  As the applicant is resident in the US and you are presumably entitled to act before RO/US, you would also be entitled to act as agent before RO/IB for the international application concerned (as would any agent entitled to practice before RO/CA). 

For further information on other issues raised in this Practical Advice (for example, permitted language(s) of filing, whether electronic filing is available at the RO, amounts of fees payable, information on restoration of the right of priority under PCT Rule 26bis.3 and criteria applied), please refer to the PCT Applicant’s Guide, Annexes B and C, in respect of the Office concerned, at:

and to find out whether an RO has any outstanding notifications of incompatibility which may influence the RO with which you may file, please refer to the table at:

Another useful resource for comparing Office information is the “Office Profile” in the “ePCT Reference Data Lookup” at:

  1. In accordance with PCT Rule 83.1bis(a), any person who has the right to practice before the national Office of, or acting for, a PCT Contracting State of which the applicant, or if there are two or more applicants, any of the applicants is resident or national shall be entitled to practice in respect of the international application before the RO/IB.

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