14.3 National Phase Entry Under 35 U.S.C. § 371

National Phase Entry Under 35 U.S.C. § 371

The culmination of the PCT international phase is the transition into individual national patent offices for substantive examination and patent grant. In the United States, this transition is governed by 35 U.S.C. § 371 and 37 C.F.R. § 1.495. National stage examination transforms the international application into an active U.S. application subject to domestic U.S. patent law, subject to specific statutory adaptations under MPEP Chapter 1800.

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1. The 30-Month Non-Extendable Deadline under 35 U.S.C. § 371

To commence national stage examination in the United States, the applicant must satisfy national stage entry requirements within a strict statutory timeframe.

The Statutory Time Limit (35 U.S.C. § 371(c)–(d) & 37 C.F.R. § 1.495(a))

Under U.S. patent law, the national stage entry deadline is 30 months from the earliest priority date (or 30 months from the international filing date if no priority is claimed).

Thirty-month requirement (MPEP 1893.01(a)): Rule 1.136 extensions do not extend the period for supplying the basic national fee and required application copy. Failure causes abandonment, but Rule 1.137 permits revival on a proper showing that the delay was unintentional. When the fee and copy are timely, missing items such as a translation or oath generally trigger a notice and surcharge rather than immediate permanent loss.

Abandonment and Revival (35 U.S.C. § 371(d) & 37 C.F.R. § 1.137)

If the applicant fails to fulfill the mandatory statutory requirements of 35 U.S.C. § 371(c) on or before the 30-month date, the international application is deemed abandoned as to the United States.

• Revival Standard: An abandoned national stage application may be revived under 37 C.F.R. § 1.137 only if the delay in meeting the 30-month requirement was unintentional.
• Revival Requirements: The petition to revive requires: (1) the petition fee specified in 37 C.F.R. § 1.17(m); (2) fulfillment of all mandatory § 371(c) requirements; and (3) a statement that the entire delay was unintentional.

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2. Mandatory Requirements for U.S. National Stage Entry

35 U.S.C. § 371(c) outlines the specific elements that must be submitted to the USPTO to establish national stage entry.

Core Statutory Requirements under 35 U.S.C. § 371(c)

To avoid abandonment at the 30-month boundary, the applicant must submit:

1. Basic National Fee (35 U.S.C. § 371(c)(1) & 37 C.F.R. § 1.492(a)): Payment of the basic national fee is mandatory by the 30-month date. Paying the basic national fee by month 30 avoids immediate abandonment.
2. English Translation (35 U.S.C. § 371(c)(2) & 37 C.F.R. § 1.495(c)): If the international application was published in a language other than English, a verified English translation of the specification, claims, abstract, and any Article 19 or Article 34 amendments must be filed.
3. Copy of International Application (35 U.S.C. § 371(c)(3)): A copy of the international application is required unless the International Bureau has already communicated a copy to the USPTO under PCT Article 20.
4. Inventor Oath or Declaration (35 U.S.C. § 371(c)(4) & 37 C.F.R. § 1.497): An oath or declaration executed by each inventor identifying themselves and acknowledging their inventor status. Under post-AIA practice, if the basic national fee and English translation are submitted by 30 months, the inventor oath/declaration may be submitted after the 30-month deadline upon payment of a late surcharge under 37 C.F.R. § 1.495(c).
5. Search Fee, Examination Fee, and Excess Claims Fees (35 U.S.C. § 371(c)(5)): The national search fee, examination fee, and any excess claims fees are due at entry but may also be supplied later with a surcharge if the basic national fee was timely paid by month 30.

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3. 35 U.S.C. § 371 National Stage vs. Bypass Continuation under 35 U.S.C. § 111(a)

Applicants seeking U.S. protection based on an international application have two procedural pathways to enter the U.S. system.

Option A: National Stage Entry under 35 U.S.C. § 371

The international application directly enters the U.S. national phase. The resulting application retains its international filing date for all prior art and examination purposes, operates under the PCT Unity of Invention standard, and preserves any Article 19 or Article 34 amendments previously filed during the international phase.

Option B: Bypass Continuation Filing under 35 U.S.C. § 111(a)

Instead of entering the national stage under § 371, the applicant files a regular U.S. nonprovisional application under 35 U.S.C. § 111(a) that claims continuation or continuation-in-part (CIP) benefit under 35 U.S.C. § 365(c) from the parent international application.

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4. Unity of Invention (PCT Rule 13) vs. Domestic U.S. Restriction (35 U.S.C. § 121)

A critical distinction tested on the Patent Bar Exam is the difference in restriction practice applied to § 371 national stage applications versus regular domestic U.S. applications.

The Unity of Invention Standard (PCT Rule 13 & MPEP 1875)

In a § 371 national stage application, restriction practice is governed exclusively by the international Unity of Invention standard under PCT Rule 13.1, rather than the traditional U.S. "independent and distinct" standard of 35 U.S.C. § 121.

• Single General Inventive Concept: Under PCT Rule 13.1, an international application must relate to one invention only or to a group of inventions so linked as to form a single general inventive concept.
• Special Technical Features (STFs): Under PCT Rule 13.2, unity of invention exists only when there is a technical relationship among the claimed inventions involving one or more of the same or corresponding special technical features. Special technical features are defined as those technical features that define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art.

USPTO Examination Handling of Lack of Unity (MPEP 1893.03(d))

If the U.S. examiner determines in a § 371 application that the claims lack Unity of Invention because they contain multiple groups lacking a common special technical feature over the prior art:

1. The examiner issues a Lack of Unity Requirement under 37 C.F.R. § 1.499.
2. The applicant must elect a single invention (or species) for initial examination.
3. The applicant may pay additional search and examination fees for un-elected inventions to have them examined in the same national stage application, or file divisional applications under 35 U.S.C. § 121 for the un-elected inventions.

In contrast, in a regular domestic application filed under § 111(a) (including bypass continuations), the examiner applies the traditional two-way distinctness and burden standard under 35 U.S.C. § 121 and MPEP Chapter 800.