Mr. Bruce A. Lehman
Assistant Secretary of Commerce and
Commissioner of Patents and Trademarks
Patent and Trademark Office
Box 4
U.S. Department of Commerce
Washington, D.C. 20231
United States of America

Dear Bruce,

I thank you for your letter of November 17, 1995, asking for our views concerning the claiming of priority under Article 4 of the Paris Convention for the Protection of Industrial Property, in respect of provisional patent applications filed with the USPTO.

As you know, the International Bureau is not in a position to give an official interpretation of the provisions of the Paris Convention. However, we offer the following considerations which may be helpful in order to reply to the question raised by you.

According to Article 4A(1) of the Paris Convention, the basis for priority under that Convention is a duly filed application for a patent.

Article 4A(2) of the Paris Convention states, in particular, that "Any filing that is equivalent to a regular national filing under the domestic legislation of any country of the Union ... shall be recognized as giving rise to the right of priority." In the case under consideration, the "domestic legislation" is the legislation of the United States of America. Therefore, it is that legislation which determines whether a "regular national filing" exists, subject to compliance with Article 4A(3) of the Paris Convention.

Article 4A(3) of the Paris Convention states that "By a regular national filing is meant any filing that is adequate to establish the date on which the application was filed in the country concerned, ... ." As section 111(b) of title 35, United States Code, establishes such a filing date with respect to provisional patent applications, this requirement of the Paris Convention appears to be satisfied. To conclude otherwise would put into question the ability of domestic legislation to prescribe the requirements which must be fulfilled for a filing to be adequate to establish a filing date.

Article 4A(3) of the Paris Convention also states that "any filing that is adequate to establish the date on which the application was filed" is a regular national filing "whatever may be the subsequent fate of the application." Thus the question of whether a filing is to be considered as a "regular national filing" does not appear to depend on whether or not that filing may itself lead to the grant of a patent. Moreover, it is to be noted that applications for patents are recognized as giving rise to a right of priority under the Paris Convention even if it is clear from the outset that no patent can be granted upon such an application, for example, where the invention concerned is excluded from patenting.

Sincerely yours,

Arpad Bogsch
Director General