PCT Newsletter

June 2025 | No. 06/2025

Practical Advice

National phase requirements where the application to which priority is claimed was assigned before the international filing date

Q.: When preparing for the national phase, I noticed that the national law of the designated Office requires certified assignment documents when the applicant claims priority to an earlier application filed by a different applicant due to an assignment. Given that this is a PCT national phase application rather than a direct national filing, am I required to furnish such certified documents?
A: Overall, it is important to distinguish between the requirements for direct national applications and those for PCT national phase applications. The PCT Treaty explicitly restricts what designated Offices may require in the national phase (Article 27 and certain situations under PCT Rule 51bis.2).​​​​​​​
While the Treaty permits national laws to require specific documents in certain cases, these instances are narrowly defined exceptions.
Pursuant to Article 27(1), (5), and (6) of the PCT, designated Offices may require evidence concerning substantive matters regarding applicants' rights, as distinct from formal requirements that were already verified during the international phase. For example, the question of whether an applicant named in a PCT application possesses rights to the invention or is entitled to claim priority from a previously filed application is a substantive matter that is not verified during the international phase.​​​​​​​
Consequently, designated Offices may in principle request evidence regarding such substantive matters, subject to the exception that if the applicant has submitted declarations during the international phase pursuant to PCT Rules 4.17 and 51bis.2, the designated Office may not generally require any evidence relating to that situation. Such declarations refer, among others, to situations where the applicant claims priority to an earlier application filed by a different applicant due to an assignment. The declarations themselves must comply with the standardized wording contained in the Administrative Instructions under the PCT (reflected in the Notes to the Request Form).
The intention of PCT Rules 4.17 and 51bis.2 is to keep cases where a designated Office requests proof or evidence to a minimum. Only exceptionally, if a designated Office reasonably doubts the veracity of the indications or the declaration, is it entitled, under PCT Rule 51bis.2, to require any document or evidence on the subject matter in question.
Please also note that, where an assignment of a priority application took place after the international filing date, such situation cannot be the subject of a PCT declaration and the designated Office may indeed require a copy of an assignment document in the form of a simple copy as evidence for your substantive rights in relation to the invention concerned. Some designated Offices do not require such evidence where the change has been the subject of a request for recording of a change reflected in a notification from the IB (Form PCT/IB/306 “Notification of the Recording of a Change”).​​​​​​​​​​​​​​​​​
In the absence of a PCT declaration filed during the international phase concerning the assignment of priority rights, a designated Office may request evidence of the assignment relating to the priority application. However, such evidence should be acceptable in the form of a simple copy of the assignment document, rather than in certified or legalized form.
PCT Rule 51bis.1(d), is the only instance in which the PCT allows national law to require something other than a simple copy. Under this provision, the designated Office may require that the translation of the internation application furnished by the applicant be:​​​​​​​

(i)   verified by the applicant or the person having translated the international application in a statement to the effect that, to the best of his knowledge, the translation is complete and faithful;
(ii)  certified by a public authority or sworn translator, but only where the designated Office may reasonably doubt the accuracy of the translation.

No comparable provision exists authorizing requirements of legalization for other types of documents.​​​​​​​
For additional information regarding the filing of declarations and their legal effects, please consult the Practical Advice published in PCT Newsletter 02/2014.
For information on submitting declarations under PCT Rule 4.17 using ePCT please refer to the ePCT User Guide FAQs.
More information on the national requirements allowed in the national phase can be found in the Practical Advice of PCT Newsletter No. 09/2017.

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