37 CFR § 1.491 - National stage commencement, entry, and fulfillment.

---
identifier: "/us/cfr/t37/s1.491"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "37 CFR § 1.491 - National stage commencement, entry, and fulfillment."
title_number: 37
title_name: "Patents, Trademarks, and Copyrights"
section_number: "1.491"
section_name: "National stage commencement, entry, and fulfillment."
chapter_name: "UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE"
subchapter_number: "A"
subchapter_name: "GENERAL"
part_number: "1"
part_name: "RULES OF PRACTICE IN PATENT CASES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "35 U.S.C. 2(b)(2), unless otherwise noted."
regulatory_source: "24 FR 10332, Dec. 22, 1959, unless otherwise noted."
cfr_part: "1"
---


# 1.491 National stage commencement, entry, and fulfillment.

(a) Subject to 35 U.S.C. 371(f), the national stage shall commence with the expiration of the applicable time limit under PCT Article 22 (1) or (2), or under PCT Article 39(1)(a).

(b) An international application enters the national stage when the applicant has filed the documents and fees required by 35 U.S.C. 371(c)(1) and (c)(2) within the period set in § 1.495.

(c) An international application fulfills the requirements of 35 U.S.C. 371 when the national stage has commenced under 35 U.S.C. 371(b) or (f) and all applicable requirements of 35 U.S.C. 371 have been satisfied.

[67 FR 523, Jan. 4, 2002, as amended at 77 FR 48823, Aug. 14, 2012]