MPEP § 602.09 — Joint Inventors (Annotated Rules)

§602.09 Joint Inventors

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

This page consolidates and annotates all enforceable requirements under MPEP § 602.09, 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.

Joint Inventors

This section addresses Joint Inventors. Primary authority: 35 U.S.C. 116, 35 U.S.C. 121, and 35 U.S.C. 120. Contains: 5 requirements, 1 guidance statement, 3 permissions, and 3 other statements.

Key Rules

Topic

AIA Effective Dates

8 rules
StatutoryRequiredAlways
[mpep-602-09-13d82991370e8681d8a79a66]
Requirement for Joint Inventors to Apply Together
Note:
Inventors must apply for a patent jointly, even if they did not work together or contribute equally.
[Editor Note: Applicable to proceedings commenced on or after September 16, 2012. See 35 U.S.C. 116 (pre-AIA) for the law otherwise applicable.]
  • (a) JOINT INVENTIONS.—When an invention is made by two or more persons jointly, they shall apply for patent jointly and each make the required oath, except as otherwise provided in this title. Inventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) each did not make the same type or amount of contribution, or (3) each did not make a contribution to the subject matter of every claim of the patent.
  • (b) OMITTED INVENTOR.—If a joint inventor refuses to join in an application for patent or cannot be found or reached after diligent effort, the application may be made by the other inventor on behalf of himself and the omitted inventor. The Director, on proof of the pertinent facts and after such notice to the omitted inventor as he prescribes, may grant a patent to the inventor making the application, subject to the same rights which the omitted inventor would have had if he had been joined. The omitted inventor may subsequently join in the application.
  • (c) CORRECTION OF ERRORS IN APPLICATION.—Whenever through error a person is named in an application for patent as the inventor, or through an error an inventor is not named in an application, the Director may permit the application to be amended accordingly, under such terms as he prescribes.
Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryRequiredAlways
[mpep-602-09-9594bbeab869079cc9021b14]
Inventors Must Apply Jointly
Note:
When an invention is made by two or more persons jointly, they must apply for a patent together and each sign the required oath.

[Editor Note: Applicable to proceedings commenced on or after September 16, 2012. See 35 U.S.C. 116 (pre-AIA) for the law otherwise applicable.] (a) JOINT INVENTIONS.—When an invention is made by two or more persons jointly, they shall apply for patent jointly and each make the required oath, except as otherwise provided in this title. Inventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) each did not make the same type or amount of contribution, or (3) each did not make a contribution to the subject matter of every claim of the patent.

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryPermittedAlways
[mpep-602-09-90c843518ff1e8e88fb35361]
Inventors May Apply Jointly Regardless of Contribution Details
Note:
Inventors can apply for a patent jointly even if they did not work together physically, simultaneously, or contribute equally to the invention.

[Editor Note: Applicable to proceedings commenced on or after September 16, 2012. See 35 U.S.C. 116 (pre-AIA) for the law otherwise applicable.] (a) JOINT INVENTIONS.—When an invention is made by two or more persons jointly, they shall apply for patent jointly and each make the required oath, except as otherwise provided in this title. Inventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) each did not make the same type or amount of contribution, or (3) each did not make a contribution to the subject matter of every claim of the patent.

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryRequiredAlways
[mpep-602-09-4840dc8cf884f9292274b644]
Correction of Inventor Errors Allowed
Note:
The Director may permit an application to be amended to correct errors in inventor naming, under terms prescribed by the Director.

[Editor Note: Applicable to proceedings commenced on or after September 16, 2012. See 35 U.S.C. 116 (pre-AIA) for the law otherwise applicable.]

(c) CORRECTION OF ERRORS IN APPLICATION.—Whenever through error a person is named in an application for patent as the inventor, or through an error an inventor is not named in an application

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryPermittedAlways
[mpep-602-09-6279ee0cd726baa70d75b269]
Director May Permit Correction of Inventor Errors
Note:
The Director may allow amendments to an application if inventors were incorrectly named or omitted, under terms he prescribes.

[Editor Note: Applicable to proceedings commenced on or after September 16, 2012. See 35 U.S.C. 116 (pre-AIA) for the law otherwise applicable.]

, the Director may permit the application to be amended accordingly, under such terms as he prescribes.

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryInformativeAlways
[mpep-602-09-82d35c939f83ce2f672caca2]
Requirement for Joint Inventorship Not Applicable Post-2012
Note:
This rule requires joint inventorship in pre-AIA proceedings but is not applicable to cases starting on or after September 16, 2012.

[Editor Note: Not applicable to proceedings commenced on or after September 16, 2012. See 35 U.S.C. 116 for the law otherwise applicable.]

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryInformativeAlways
[mpep-602-09-8b3ccddedd8c2b881e4f9a0d]
Inventorship Correction Requirement After September 16, 2012
Note:
Requests to correct inventorship under 37 CFR 1.48 must be filed on or after September 16, 2012, and are processed by OPAP when claims are amended.

Applicants are responsible for correcting, and are required to correct, the inventorship in compliance with 37 CFR 1.48 when the application is amended to change the claims so that one (or more) of the named inventors is no longer an inventor of the subject matter of a claim remaining in the application. Requests under 37 CFR 1.48 filed on or after September 16, 2012 (regardless of the application filing date) are treated by OPAP. If the request is granted, OPAP will correct the Office records and send a corrected filing receipt.

Jump to MPEP Source · 37 CFR 1.48AIA Effective DatesAIA Overview and Effective DatesInventorship Under AIA
StatutoryInformativeAlways
[mpep-602-09-492927c7531081233947aecc]
Request to Correct Inventorship Must Be Filed
Note:
Applicants must file a request with OPAP to correct inventorship when claims are amended, and the request will be granted if it is filed on or after September 16, 2012.

Applicants are responsible for correcting, and are required to correct, the inventorship in compliance with 37 CFR 1.48 when the application is amended to change the claims so that one (or more) of the named inventors is no longer an inventor of the subject matter of a claim remaining in the application. Requests under 37 CFR 1.48 filed on or after September 16, 2012 (regardless of the application filing date) are treated by OPAP. If the request is granted, OPAP will correct the Office records and send a corrected filing receipt.

Jump to MPEP Source · 37 CFR 1.48AIA Effective DatesAIA Overview and Effective DatesInventorship Under AIA
Topic

Distinct Inventions (MPEP 802.01)

8 rules
StatutoryRequiredAlways
[mpep-602-09-9727c92444d6404b5da6521e]
Necessity to Change Inventorship if Elected Invention Not Originally Named
Note:
If an application by joint inventors includes more than one independent and distinct invention, the elected invention may require a change in inventorship if it was not originally named.

Like other patent applications, jointly filed applications are subject to the requirements of 35 U.S.C. 121 that an application be directed to only a single invention. If an application by joint inventors includes more than one independent and distinct invention, restriction may be required with the possible result of a necessity to change the inventorship named in the application if the elected invention was not the invention of all the originally named inventors. In such a case, a “divisional” application complying with 35 U.S.C. 120 would be entitled to the benefit of the earlier filing date of the original application. In requiring restriction in an application filed by joint inventors, the examiner should remind applicants of the necessity to correct the inventorship pursuant to 37 CFR 1.48 if an invention is elected and the claims to the invention of one or more inventors are canceled.

Jump to MPEP Source · 37 CFR 1.48Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryInformativeAlways
[mpep-602-09-f886ae29954e5cebc0417048]
Divisional Application Entitled to Earlier Filing Date
Note:
A divisional application that complies with 35 U.S.C. 120 is entitled to the filing date of the original application if it includes only one invention.

Like other patent applications, jointly filed applications are subject to the requirements of 35 U.S.C. 121 that an application be directed to only a single invention. If an application by joint inventors includes more than one independent and distinct invention, restriction may be required with the possible result of a necessity to change the inventorship named in the application if the elected invention was not the invention of all the originally named inventors. In such a case, a “divisional” application complying with 35 U.S.C. 120 would be entitled to the benefit of the earlier filing date of the original application. In requiring restriction in an application filed by joint inventors, the examiner should remind applicants of the necessity to correct the inventorship pursuant to 37 CFR 1.48 if an invention is elected and the claims to the invention of one or more inventors are canceled.

Jump to MPEP Source · 37 CFR 1.48Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryRecommendedAlways
[mpep-602-09-559983009403bf7c504d4b66]
Requirement to Correct Inventorship After Restriction
Note:
Examiners must remind applicants to correct inventorship using 37 CFR 1.48 if an elected invention is claimed by one or more inventors who did not originally contribute.

Like other patent applications, jointly filed applications are subject to the requirements of 35 U.S.C. 121 that an application be directed to only a single invention. If an application by joint inventors includes more than one independent and distinct invention, restriction may be required with the possible result of a necessity to change the inventorship named in the application if the elected invention was not the invention of all the originally named inventors. In such a case, a “divisional” application complying with 35 U.S.C. 120 would be entitled to the benefit of the earlier filing date of the original application. In requiring restriction in an application filed by joint inventors, the examiner should remind applicants of the necessity to correct the inventorship pursuant to 37 CFR 1.48 if an invention is elected and the claims to the invention of one or more inventors are canceled.

Jump to MPEP Source · 37 CFR 1.48Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryPermittedAlways
[mpep-602-09-acf7aa36d1d7207cdec4af38]
Different Claims May Have Different Invention Dates
Note:
Patent claims may have varying dates of invention even if they cover a single distinct invention.

35 U.S.C. 116 increases the likelihood that different claims of an application or patent may have different dates of invention even though the patent covers only one independent and distinct invention within the meaning of 35 U.S.C. 121. The examiner should not inquire of the patent applicant concerning the inventors and the invention dates for the subject matter of the various claims until it becomes necessary to do so in order to properly examine the application. If an application is filed with joint inventors, the examiner should assume that the subject matter of the various claims was commonly owned at the time the inventions covered therein were made, unless there is evidence to the contrary. When necessary, the U.S. Patent and Trademark Office or a court may inquire of the patent applicant or owner the inventorship or ownership of each claimed invention on its effective filing date, or on its date of invention, as applicable. 37 CFR 1.110. Pending nonprovisional applications will be permitted to be amended by complying with 37 CFR 1.48 to add claims to inventions by inventors not named when the application was filed as long as such inventions were disclosed in the application as filed since 37 CFR 1.48 permits correction of inventorship where the correct inventor or inventors are not named in an application for patent.

Jump to MPEP Source · 37 CFR 1.110Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryRecommendedAlways
[mpep-602-09-f7046ef484201865e4f160d4]
Examiner Should Not Inquire About Inventors Until Necessary
Note:
The examiner should not ask about inventors and invention dates until needed to properly examine the application.

35 U.S.C. 116 increases the likelihood that different claims of an application or patent may have different dates of invention even though the patent covers only one independent and distinct invention within the meaning of 35 U.S.C. 121. The examiner should not inquire of the patent applicant concerning the inventors and the invention dates for the subject matter of the various claims until it becomes necessary to do so in order to properly examine the application. If an application is filed with joint inventors, the examiner should assume that the subject matter of the various claims was commonly owned at the time the inventions covered therein were made, unless there is evidence to the contrary. When necessary, the U.S. Patent and Trademark Office or a court may inquire of the patent applicant or owner the inventorship or ownership of each claimed invention on its effective filing date, or on its date of invention, as applicable. 37 CFR 1.110. Pending nonprovisional applications will be permitted to be amended by complying with 37 CFR 1.48 to add claims to inventions by inventors not named when the application was filed as long as such inventions were disclosed in the application as filed since 37 CFR 1.48 permits correction of inventorship where the correct inventor or inventors are not named in an application for patent.

Jump to MPEP Source · 37 CFR 1.110Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryRecommendedAlways
[mpep-602-09-0b04094025749f788a7cdbac]
Assume Common Ownership for Joint Inventors Unless Proven Otherwise
Note:
If an application is filed with joint inventors, the examiner should assume that all claims share common ownership at the time of invention unless evidence proves otherwise.

35 U.S.C. 116 increases the likelihood that different claims of an application or patent may have different dates of invention even though the patent covers only one independent and distinct invention within the meaning of 35 U.S.C. 121. The examiner should not inquire of the patent applicant concerning the inventors and the invention dates for the subject matter of the various claims until it becomes necessary to do so in order to properly examine the application. If an application is filed with joint inventors, the examiner should assume that the subject matter of the various claims was commonly owned at the time the inventions covered therein were made, unless there is evidence to the contrary. When necessary, the U.S. Patent and Trademark Office or a court may inquire of the patent applicant or owner the inventorship or ownership of each claimed invention on its effective filing date, or on its date of invention, as applicable. 37 CFR 1.110. Pending nonprovisional applications will be permitted to be amended by complying with 37 CFR 1.48 to add claims to inventions by inventors not named when the application was filed as long as such inventions were disclosed in the application as filed since 37 CFR 1.48 permits correction of inventorship where the correct inventor or inventors are not named in an application for patent.

Jump to MPEP Source · 37 CFR 1.110Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryPermittedAlways
[mpep-602-09-1bc3d9d618a76bf82498a052]
Patent Office May Inquire About Inventorship and Ownership
Note:
The U.S. Patent and Trademark Office may ask the patent applicant about the inventorship and ownership of each claimed invention on its effective filing date or date of invention when necessary.

35 U.S.C. 116 increases the likelihood that different claims of an application or patent may have different dates of invention even though the patent covers only one independent and distinct invention within the meaning of 35 U.S.C. 121. The examiner should not inquire of the patent applicant concerning the inventors and the invention dates for the subject matter of the various claims until it becomes necessary to do so in order to properly examine the application. If an application is filed with joint inventors, the examiner should assume that the subject matter of the various claims was commonly owned at the time the inventions covered therein were made, unless there is evidence to the contrary. When necessary, the U.S. Patent and Trademark Office or a court may inquire of the patent applicant or owner the inventorship or ownership of each claimed invention on its effective filing date, or on its date of invention, as applicable. 37 CFR 1.110. Pending nonprovisional applications will be permitted to be amended by complying with 37 CFR 1.48 to add claims to inventions by inventors not named when the application was filed as long as such inventions were disclosed in the application as filed since 37 CFR 1.48 permits correction of inventorship where the correct inventor or inventors are not named in an application for patent.

Jump to MPEP Source · 37 CFR 1.110Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
StatutoryPermittedAlways
[mpep-602-09-4d3ec94cbc4ce86296822177]
Pending Nonprovisional Applications Can Add Claims by Unnamed Inventors
Note:
Pending nonprovisional applications can add claims for inventions not named in the original filing as long as those inventions were disclosed.

35 U.S.C. 116 increases the likelihood that different claims of an application or patent may have different dates of invention even though the patent covers only one independent and distinct invention within the meaning of 35 U.S.C. 121. The examiner should not inquire of the patent applicant concerning the inventors and the invention dates for the subject matter of the various claims until it becomes necessary to do so in order to properly examine the application. If an application is filed with joint inventors, the examiner should assume that the subject matter of the various claims was commonly owned at the time the inventions covered therein were made, unless there is evidence to the contrary. When necessary, the U.S. Patent and Trademark Office or a court may inquire of the patent applicant or owner the inventorship or ownership of each claimed invention on its effective filing date, or on its date of invention, as applicable. 37 CFR 1.110. Pending nonprovisional applications will be permitted to be amended by complying with 37 CFR 1.48 to add claims to inventions by inventors not named when the application was filed as long as such inventions were disclosed in the application as filed since 37 CFR 1.48 permits correction of inventorship where the correct inventor or inventors are not named in an application for patent.

Jump to MPEP Source · 37 CFR 1.110Distinct Inventions (MPEP 802.01)Basis for Restriction (MPEP 802)Restriction Requirement (MPEP 802-803)
Topic

Inventor's Oath/Declaration Requirements

1 rules
StatutoryRequiredAlways
[mpep-602-09-471fc904f641e87985049ad7]
Requirement for Joint Patent Application and Oath by Each Inventor
Note:
Inventors must apply jointly for a patent and each make the required oath, unless otherwise specified in this title.

When an invention is made by two or more persons jointly, they shall apply for patent jointly and each make the required oath, except as otherwise provided in this title. Inventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) each did not make the same type or amount of contribution, or (3) each did not make a contribution to the subject matter of every claim of the patent.

Jump to MPEP SourceInventor's Oath/Declaration RequirementsAIA vs Pre-AIA Practice
Topic

AIA vs Pre-AIA Practice

1 rules
StatutoryPermittedAlways
[mpep-602-09-1c1ef467d4f3d74ac3d92e33]
Inventors May Apply Jointly Regardless of Contribution Differences
Note:
Inventors can apply for a patent jointly even if they did not work together physically, at the same time, or contribute equally to the invention.

When an invention is made by two or more persons jointly, they shall apply for patent jointly and each make the required oath, except as otherwise provided in this title. Inventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) each did not make the same type or amount of contribution, or (3) each did not make a contribution to the subject matter of every claim of the patent.

Jump to MPEP SourceAIA vs Pre-AIA PracticeInventor's Oath/Declaration Requirements
Topic

Inventor Signature Requirements

1 rules
StatutoryRequiredAlways
[mpep-602-09-85059f471f7554e71ddfc2f1]
Joint Inventors Must Sign Same Oath
Note:
Joint inventors must make the required oath or declaration in a nonprovisional application by signing the same document, rather than separately signing the application.

Joint inventors do not have to separately “sign the application,” but only need apply for the patent jointly and make the required oath or declaration in a nonprovisional application by signing the same. See MPEP §§ 602.01(a) and 602.01(b).

Jump to MPEP Source · 37 CFR 1.45Inventor Signature RequirementsSignature Requirements
Topic

Inventorship Under AIA

1 rules
StatutoryRequiredAlways
[mpep-602-09-c45fe011fa6862c61653edff]
Inventorship Must Be Corrected When Claims Change
Note:
Applicants must update inventorship in compliance with 37 CFR 1.48 when claims are amended to exclude an inventor.

Applicants are responsible for correcting, and are required to correct, the inventorship in compliance with 37 CFR 1.48 when the application is amended to change the claims so that one (or more) of the named inventors is no longer an inventor of the subject matter of a claim remaining in the application. Requests under 37 CFR 1.48 filed on or after September 16, 2012 (regardless of the application filing date) are treated by OPAP. If the request is granted, OPAP will correct the Office records and send a corrected filing receipt.

Jump to MPEP Source · 37 CFR 1.48Inventorship Under AIAAIA Effective DatesAIA Overview and Effective Dates
Topic

Restriction Requirement (MPEP 802-803)

1 rules
StatutoryInformativeAlways
[mpep-602-09-dc95c65a40b81d9d5eaab73f]
Restriction Required for Joint Inventors
Note:
Joint inventors must restrict their application to a single invention as required by 35 U.S.C. 121, or face potential changes in inventorship and the need for divisional applications.

Like other patent applications, jointly filed applications are subject to the requirements of 35 U.S.C. 121 that an application be directed to only a single invention. If an application by joint inventors includes more than one independent and distinct invention, restriction may be required with the possible result of a necessity to change the inventorship named in the application if the elected invention was not the invention of all the originally named inventors. In such a case, a “divisional” application complying with 35 U.S.C. 120 would be entitled to the benefit of the earlier filing date of the original application. In requiring restriction in an application filed by joint inventors, the examiner should remind applicants of the necessity to correct the inventorship pursuant to 37 CFR 1.48 if an invention is elected and the claims to the invention of one or more inventors are canceled.

Jump to MPEP Source · 37 CFR 1.48Restriction Requirement (MPEP 802-803)Restriction and Election Practice (MPEP Chapter 800)Distinct Inventions (MPEP 802.01)

Citations

Primary topicCitation
AIA Effective Dates
Distinct Inventions (MPEP 802.01)
35 U.S.C. § 116
Distinct Inventions (MPEP 802.01)
Restriction Requirement (MPEP 802-803)
35 U.S.C. § 120
Distinct Inventions (MPEP 802.01)
Restriction Requirement (MPEP 802-803)
35 U.S.C. § 121
Distinct Inventions (MPEP 802.01)37 CFR § 1.110
37 CFR § 1.45
37 CFR § 1.45(c)
AIA Effective Dates
Distinct Inventions (MPEP 802.01)
Inventorship Under AIA
Restriction Requirement (MPEP 802-803)
37 CFR § 1.48
MPEP § 2109.01
Inventor Signature RequirementsMPEP § 602.01(a)

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