MPEP § 823 — Unity of Invention Under the Patent Cooperation Treaty (Annotated Rules)

§823 Unity of Invention Under the Patent Cooperation Treaty

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 823, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Unity of Invention Under the Patent Cooperation Treaty

This section addresses Unity of Invention Under the Patent Cooperation Treaty. Primary authority: 35 U.S.C. 371, 35 U.S.C. 111(a), and 35 U.S.C. 1875. Contains: 1 permission.

Key Rules

Topic

Amendments in National Stage

1 rules
StatutoryPermittedAlways
[mpep-823-d796721bd25354ad9a12c1b3]
Differences in Unity of Invention Analysis for National Stage Applications Under 35 U.S.C. 371 vs 111(a)
Note:
The analysis to determine whether the Office may require restriction differs between national stage applications submitted under 35 U.S.C. 371 and those filed under 35 U.S.C. 111(a).

The analysis used to determine whether the Office may require restriction differs in national stage applications submitted under 35 U.S.C. 371 (unity of invention analysis) as compared to national applications filed under 35 U.S.C. 111(a) (independent and distinct analysis). See MPEP Chapter 1800, in particular MPEP § 1850, § 1875, and § 1893.03(d), for a detailed discussion of unity of invention under the Patent Cooperation Treaty (PCT). However, the guidance set forth in this chapter with regard to other substantive and procedural matters (e.g., double patenting rejections (MPEP § 804), election and reply by applicant (MPEP § 818), and rejoinder of nonelected inventions (MPEP § 821.04) generally applies to national stage applications submitted under 35 U.S.C. 371.

Jump to MPEP Source · 37 CFR 1893.03(d)Amendments in National StageUnity of Invention StandardNational Stage Examination

Citations

Primary topicCitation
Amendments in National Stage35 U.S.C. § 111(a)
Amendments in National Stage35 U.S.C. § 1875
Amendments in National Stage35 U.S.C. § 371
Amendments in National Stage37 CFR § 1893.03(d)
Amendments in National StageMPEP § 1850
Amendments in National StageMPEP § 804
Amendments in National StageMPEP § 818
Amendments in National StageMPEP § 821.04

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31