PA 01/2020: Signatures in the case where no agent has been appointed and there is more than one applicant; appointment of a common representative

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:  I am going to file an international application together with another applicant.  For financial reasons, we prefer not to use the services of an agent at this stage, and to deal with all the necessary formalities for the filing of the application ourselves.  Is this possible, and if so, do we both need to sign all the documents in connection with the application, or can one of us do so on behalf of the other?

A: In the majority of cases, the receiving Office does not require the appointment of an agent, or it requires the appointment of an agent only if the applicant is not resident in the country of filing of the international application.  There are, however, a few Offices that require the appointment of an agent in all cases, so please check this before filing.  The requirements for each receiving Office regarding the appointment of agents, where they have been furnished to the International Bureau, are indicated at or near the end of Annex C (for each Office concerned) of the PCT Applicant’s Guide (  Note that if you use ePCT to prepare your application, the ePCT‑Filing software provides a validation message if the appointment of an agent is required by the selected receiving Office, but an agent has not already been added.

For the purposes of this Practical Advice, we will presume that the competent receiving Office with which you intend to file the international application does not require the appointment of an agent.  Even though you are permitted to file with that receiving Office without appointing an agent, it would, however, be very prudent to benefit from the knowledge and expertise of a patent attorney who is experienced in the filing of patent applications, in particular PCT applications, as well as in the drafting of patent claims.  We highly recommend that you request assistance from such an agent in order to avoid any possible loss of rights.  The PCT procedure can be fairly complex for anyone who is not an experienced user, even though there are many safeguards when filing and managing the international application using an electronic filing system such as ePCT.  You should bear in mind that you would not be able to make certain modifications to the application, such as adding new matter, after the international filing date.  This means that you need to ensure that, upon filing, your application contains all the information necessary to properly disclose your invention.  A patent attorney can also give you strategic advice, taking into account the specificities of the invention. 

Furthermore, please be aware that, for the purposes of entering the national phase in the countries which are of interest to you, many designated (or elected) Offices will, in any case, require the appointment of an agent who practices in the country concerned, and in any case, the national phase procedure requires a good knowledge of the applicable national law.  For further information on national phase requirements regarding the appointment of agents, please refer to the National Chapters (Summaries) in the PCT Applicant’s Guide for each country where you seek protection.

If you decide to proceed with the application without appointing an agent in the international phase, either you or your co‑applicant can act as common representative (provided that whoever acts as common representative is a national and/or resident of a PCT Contracting State) and carry out all the necessary steps on behalf of the other applicant during the international phase.  The common representative should preferably be indicated in Box No. IV of the request form or, if filing electronically using ePCT-Filing, by entering the relevant information after clicking on the button to add “Agent/Common representative/Address for correspondence”.  Note that if no indication of an agent or common representative is given in the request form, one of you will be deemed to be the common representative.  In accordance with PCT Rule 90.2(b), the “deemed” common representative would be the first‑named applicant in the request who is entitled, according to PCT Rule 19.1, to file an international application with the selected receiving Office. 

If you are the person who will act as common representative, the other applicant can appoint you as such by:

–    signing the request form in which you are named specifically as common representative (or in which you, presuming that you are entitled to file an international application with the receiving Office, are the first-named applicant in the request form); or

–    signing and submitting to the receiving Office a separate or general power of attorney appointing you as a common representative (models of those forms are available at:

As a duly appointed common representative (as opposed to a “deemed” common representative), you would then be able to carry out all actions in respect of the international application on behalf of your co-applicant, including the submission of requests for changes under PCT Rule 92bis, amendments to the claims under PCT Article 19, the filing of a demand for international preliminary examination, as well as the withdrawal of the international application, any designations, any priority claims, a demand or any elections.

If you have signed the request form (in which you are either indicated as common representative or you are the “deemed” common representative) but the other applicant has not signed it, and a power of attorney appointing you as common representative has not been submitted by the other applicant, the lack of signature of the request form will not be considered a defect, given that PCT Rule 26.2bis states that it is sufficient if it is signed by at least one applicant.  In fact most actions that you, as deemed common representative, take regarding the international application would have the effect of an act by both applicants.  You would not, however, be entitled to withdraw the international application, any designations, any priority claims, a demand or any elections without the signature of your co‑applicant (PCT Rule 90bis.5).  This is because any notice of withdrawal requires the signature of all applicants, unless it has been signed on behalf of the other applicant(s) by a duly appointed agent, a duly appointed common representative, or the agent of the latter.

Before you file your international application, please ensure that you are fully aware of all the costs involved in filing an international application, entering the national phase in the various countries in which you might wish to have protection, and in maintaining the patent, if granted.  These can be found in the various annexes of the PCT Applicant’s Guide

For further information on common representatives, please refer to paragraph 11.005 to 11.007 and 11.10 to 11.14 of the PCT Applicants Guide – International Phase.

6 references found.

Click X to load a reference inside the current page, click on the title to open in a new page.

PCT Articles

PCT Implementing Rules