37 CFR § 41.4 - Timeliness.

---
identifier: "/us/cfr/t37/s41.4"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "37 CFR § 41.4 - Timeliness."
title_number: 37
title_name: "Patents, Trademarks, and Copyrights"
section_number: "41.4"
section_name: "Timeliness."
chapter_name: "UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE"
subchapter_number: "A"
subchapter_name: "GENERAL"
part_number: "41"
part_name: "PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "35 U.S.C. 2(b)(2), 3(a)(2)(A), 21, 23, 32, 41, 134, 135, and Public Law 112-29."
regulatory_source: "69 FR 50003, Aug. 12, 2004, unless otherwise noted."
cfr_part: "41"
---


# 41.4 Timeliness.

(a) *Extensions of time.* Extensions of time will be granted only on a showing of good cause except as otherwise provided by rule.

(b) *Late filings.* (1) A late filing that results in either an application becoming abandoned or a reexamination prosecution becoming terminated under § 1.550(d) or § 1.957(b) of this title or limited under § 1.957(c) of this title may be revived as set forth in § 1.137 of this title.

(2) A late filing that does not result in either an application becoming abandoned or a reexamination prosecution becoming terminated under § 1.550(d) or § 1.957(b) of this title or limited under § 1.957(c) of this title will be excused upon a showing of excusable neglect or a Board determination that consideration on the merits would be in the interest of justice.

(c) *Scope.* This section governs all proceedings before the Board, but does not apply to filings related to Board proceedings before or after the Board has jurisdiction, such as:

(1) Extensions during prosecution (see § 1.136 of this title),

(2) Filing of a brief or request for oral hearing (see §§ 41.37, 41.41, 41.47, 41.67, 41.68, 41.71 and 41.73), or

(3) Seeking judicial review (see §§ 1.301 to 1.304 of this title).

[69 FR 50003, Aug. 12, 2004, as amended at 72 FR 18907, Apr. 16, 2007]