A PCT application allows an applicant to secure a filing date for an invention, while leaving the decision regarding which PCT countries to pursue patent protection in for another (much later) date. The international stage of a PCT application extends 30 or 31 months from the priority date of the PCT application in most PCT countries, allowing an applicant time to market his or her invention prior to committing to the substantial expense of national stage entry and prosecution potentially in multiple countries. Additionally, the results of a patentability search performed by the selected search authority during the international stage may be an indicator of the likelihood of successfully obtaining patent protection, and may be informative of claim amendments that can be made to arrive at patentable scope.

If the applicant ultimately decides to seek protection in the United States, he or she is faced with another choice: whether to proceed with traditional national stage entry of the PCT application under 35 U.S.C. 371, or instead file a nonprovisional application under 35 U.S.C. 111(a) claiming priority to the PCT application. With respect to the latter, as long as the PCT application designates the United States, a continuation, divisional, or continuation-in-part application claiming the benefit of the filing date of the PCT application may be filed while the PCT application is pending. See 35 U.S.C. 111(a), 37 C.F.R. 1.53(b), MPEP 211.01(c). An application filed under Section 1.111 claiming priority to a PCT application has historically been referred to as a “bypass continuation” as it bypassed the pre-AIA requirements for national stage entry under 35 U.S.C. 371(c), and so was often used by applicants unable to produce an oath or declaration or a submission of an English-language translation of the international application by the national stage entry deadline.

Prior Art Consideration

One benefit of a bypass continuation-in-part application is the ability to expand the disclosure to add new embodiments developed since the international filing date. In contrast, no new matter may be added under the national stage entry option. One must beware, however, that in some circumstances, the PCT application will be considered prior art against any claims supported only by the new content of the bypass continuation-in-part application. For example, 35 U.S.C. 102(a) recites that, “[a] person shall be entitled to a patent unless (1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention”. One exception to Section 102(a)(1) is that a disclosure made one year or less before the effective filing date of a claimed invention is not prior art if the disclosure was made by the inventor or joint inventor or by another who obtained the subject matter disclosed directly or indirectly from the inventor or a joint inventor. See 35 U.S.C. 102(b)(1).

Timing as a Critical Component

If the PCT application published more than one year prior to filing of the bypass continuation-in-part application, the Section 102(a)(1) bar to patentability is triggered. For this reason, if a bypass continuation-in-part route is a possibility, it should be docketed for consideration and filing not more than 12 months after the publication date of the PCT application, and ideally prior to the publication date of the PCT. Under PCT Article 21, publication of the PCT application occurs promptly after the expiration of 18 months from the earliest priority date of the PCT application. Accordingly, while a PCT application is in the international stage, practitioners should calendar the expected publication date of the PCT application and monitor an applicant’s continuing innovation to make the best choice between national stage entry and the bypass continuation-in-part route.

Unity of Invention Versus U.S. Restriction Practice

Another consideration regarding traditional national stage entry versus the bypass continuation route is the impact of unity of invention practice versus U.S. restriction practice. The application is subject to the unity of invention requirement if the 371(c) national stage entry route is followed, and to U.S. restriction practice if the Section 111(a) continuation route is followed. The requirement for unity of invention is found in PCT Rule 13.1 which states that, “the international application shall relate to one invention only or to a group of inventions so linked as to form a single general inventive concept”. If claims to different inventions are set forth, the requirement of unity of invention is nevertheless fulfilled when there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features. The expression “special technical features” shall mean those technical features that define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art. See PCT Rule 13.2. Accordingly, prosecuting the claims in a single application in the U.S. under the national stage entry route may require that each of the independent claims recites the special technical feature. An applicant choosing the national stage entry route should thus weigh any narrowing effect of the requirement for the special technical feature in each independent claim under the unity of invention standard against any cost savings of prosecuting and maintaining a single application.

In contrast to a national stage application, a bypass continuation application will be examined under U.S. restriction practice, which provides that, “a restriction requirement is proper when two or more independent and distinct inventions are recited in the claims.” 37 C.F.R. 1.141. In practice, Section 1.141 is applied to require an election when the examiner finds independent or distinct inventions recited in the claims, and an election of species may also be required where the Examiner notes distinct species (e.g., multiple embodiments). A restriction requirement under Section 1.141 comes with a safe harbor against a double patenting rejection of a divisional application pursuing a restricted invention or species. More specifically, 35 U.S.C. § 121 provides that, “[a] patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference . . . against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application.” The USPTO extends the safe harbor to national stage applications examined under unity of invention practice as well, noting in MPEP 804.01 that, “the prohibition against non-statutory double patenting rejections does apply to requirements for restriction (lack of unity of invention holdings) made in national stage applications submitted under 35 U.S.C. 371.”


The bypass continuation route may be the road less traveled, but should be considered as an alternative to or in addition to a national stage application. During the international stage, applicants should consider continuing innovation and relative costs of the subsequent entry/filing decision, all while monitoring the publication date of the PCT.