MPEP § 409.03(a) — At Least One Joint Inventor Available (Annotated Rules)

§409.03(a) At Least One Joint Inventor Available

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

This page consolidates and annotates all enforceable requirements under MPEP § 409.03(a), 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.

At Least One Joint Inventor Available

This section addresses At Least One Joint Inventor Available. Primary authority: 35 U.S.C. 116, 35 U.S.C. 111(a), and 37 CFR 1.47(a). Contains: 3 requirements, 2 prohibitions, and 1 permission.

Key Rules

Topic

AIA vs Pre-AIA Practice

4 rules
StatutoryProhibitedAlways
[mpep-409-03-a-a3ec0add14a958244917fe1a]
Requirement for Joint Inventors to File on Behalf of Unlocatable or Refusing Co-Inventors
Note:
All available joint inventors must file an application on behalf of themselves and any co-inventor who cannot be found or refuses to join in the application after diligent effort.

Pre-AIA 37 CFR 1.47(a) and pre-AIA 35 U.S.C. 116, second paragraph, requires all available joint inventors to file an application “on behalf of” themselves and on behalf of a joint inventor who “cannot be found or reached after diligent effort” or who refuses to “join in an application.”

Jump to MPEP Source · 37 CFR 1.47(a)AIA vs Pre-AIA PracticeDisclosure Requirements
StatutoryRequiredAlways
[mpep-409-03-a-78d0e53a99e90327f0385fd2]
Oath/Declaration for Non-Signing Inventors Required
Note:
An application must include oaths or declarations from all joint inventors, including those who cannot be found or refuse to sign.
In addition to other requirements of law (pre-AIA 35 U.S.C. 111(a) and 115), an application deposited in the U.S. Patent and Trademark Office pursuant to pre-AIA 37 CFR 1.47(a) must meet the following requirements:
  • (A) All the available joint inventors must (1) make oath or declaration on their own behalf as required by pre-AIA 37 CFR 1.63 or 1.175 (see MPEP §§ 602, 605.01, 602.09, and 1414) and (2) make oath or declaration on behalf of the nonsigning joint inventor as required by pre-AIA 37 CFR 1.64. An oath or declaration signed by all the available joint inventors with the signature block of the nonsigning inventor(s) left blank may be treated as having been signed by all the available joint inventors on behalf of the nonsigning inventor(s), unless otherwise indicated.
  • (B) The application must be accompanied by proof that the nonsigning inventor (1) cannot be found or reached after diligent effort or (2) refuses to execute the application papers. See MPEP § 409.03(d).
  • (C) The last known address of the nonsigning joint inventor must be stated. See MPEP § 409.03(e).
Jump to MPEP Source · 37 CFR 1.47(a)AIA vs Pre-AIA PracticeCircumstances Requiring Substitute StatementContent of Substitute Statement
StatutoryProhibitedAlways
[mpep-409-03-a-41a1275932312b57739a3289]
Proof of Nonsigning Inventor's Unavailability or Refusal Required
Note:
The application must include proof that the nonsigning inventor cannot be found or reached after diligent effort, or refuses to sign the application papers.

In addition to other requirements of law (pre-AIA 35 U.S.C. 111(a) and 115), an application deposited in the U.S. Patent and Trademark Office pursuant to pre-AIA 37 CFR 1.47(a) must meet the following requirements:

(B) The application must be accompanied by proof that the nonsigning inventor (1) cannot be found or reached after diligent effort or (2) refuses to execute the application papers. See MPEP § 409.03(d).

Jump to MPEP Source · 37 CFR 1.47(a)AIA vs Pre-AIA Practice
StatutoryRequiredAlways
[mpep-409-03-a-3ccf4fcd13c05703a093dcaa]
Last Known Address of Nonsigning Joint Inventor Must Be Stated
Note:
The application must include the last known address of any joint inventor who did not sign the application.

In addition to other requirements of law (pre-AIA 35 U.S.C. 111(a) and 115), an application deposited in the U.S. Patent and Trademark Office pursuant to pre-AIA 37 CFR 1.47(a) must meet the following requirements:

(C) The last known address of the nonsigning joint inventor must be stated. See MPEP § 409.03(e).

Jump to MPEP Source · 37 CFR 1.47(a)AIA vs Pre-AIA Practice
Topic

AIA Oath/Declaration Requirements (37 CFR 1.63)

1 rules
StatutoryRequiredAlways
[mpep-409-03-a-e6281be7e976423cd2543a5d]
Oath/Declaration Requirement for Joint Inventors
Note:
All joint inventors must make oath or declaration on their own behalf and on behalf of any nonsigning co-inventor as required by pre-AIA regulations.

In addition to other requirements of law (pre-AIA 35 U.S.C. 111(a) and 115), an application deposited in the U.S. Patent and Trademark Office pursuant to pre-AIA 37 CFR 1.47(a) must meet the following requirements (A) All the available joint inventors must (1) make oath or declaration on their own behalf as required by pre-AIA 37 CFR 1.63 or 1.175 (see MPEP §§ 602, 605.01, 602.09, and 1414) and (2) make oath or declaration on behalf of the nonsigning joint inventor as required by pre-AIA 37 CFR 1.64. An oath or declaration signed by all the available joint inventors with the signature block of the nonsigning inventor(s) left blank may be treated as having been signed by all the available joint inventors on behalf of the nonsigning inventor(s), unless otherwise indicated.

Jump to MPEP Source · 37 CFR 1.47(a)AIA Oath/Declaration Requirements (37 CFR 1.63)Pre-AIA Oath/Declaration RequirementsInventor Oath/Declaration Signature
Topic

Inventor's Oath/Declaration Requirements

1 rules
StatutoryPermittedAlways
[mpep-409-03-a-ec809c0ca9fd11a950fda3d7]
Oath for Non-Signing Inventors
Note:
An oath signed by all available joint inventors can be treated as signed on behalf of nonsigning inventors, unless otherwise indicated.

In addition to other requirements of law (pre-AIA 35 U.S.C. 111(a) and 115), an application deposited in the U.S. Patent and Trademark Office pursuant to pre-AIA 37 CFR 1.47(a) must meet the following requirements (A) All the available joint inventors must (1) make oath or declaration on their own behalf as required by pre-AIA 37 CFR 1.63 or 1.175 (see MPEP §§ 602, 605.01, 602.09, and 1414) and (2) make oath or declaration on behalf of the nonsigning joint inventor as required by pre-AIA 37 CFR 1.64. An oath or declaration signed by all the available joint inventors with the signature block of the nonsigning inventor(s) left blank may be treated as having been signed by all the available joint inventors on behalf of the nonsigning inventor(s), unless otherwise indicated.

Jump to MPEP Source · 37 CFR 1.47(a)Inventor's Oath/Declaration RequirementsInventor Signature RequirementsSignature Requirements

Citations

Primary topicCitation
AIA Oath/Declaration Requirements (37 CFR 1.63)
AIA vs Pre-AIA Practice
Inventor's Oath/Declaration Requirements
35 U.S.C. § 111(a)
AIA vs Pre-AIA Practice35 U.S.C. § 116
AIA Oath/Declaration Requirements (37 CFR 1.63)
AIA vs Pre-AIA Practice
Inventor's Oath/Declaration Requirements
37 CFR § 1.47(a)
AIA Oath/Declaration Requirements (37 CFR 1.63)
AIA vs Pre-AIA Practice
Inventor's Oath/Declaration Requirements
37 CFR § 1.63
AIA Oath/Declaration Requirements (37 CFR 1.63)
AIA vs Pre-AIA Practice
Inventor's Oath/Declaration Requirements
37 CFR § 1.64
AIA vs Pre-AIA PracticeMPEP § 409.03(d)
AIA vs Pre-AIA PracticeMPEP § 409.03(e)
AIA Oath/Declaration Requirements (37 CFR 1.63)
AIA vs Pre-AIA Practice
Inventor's Oath/Declaration Requirements
MPEP § 602

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