MPEP § 509.03(a) — Duty to Investigate Entitlement to Claim Small Entity Status (Annotated Rules)

§509.03(a) Duty to Investigate Entitlement to Claim Small Entity Status

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

This page consolidates and annotates all enforceable requirements under MPEP § 509.03(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.

Duty to Investigate Entitlement to Claim Small Entity Status

This section addresses Duty to Investigate Entitlement to Claim Small Entity Status. Primary authority: 37 CFR 1.27(f) and 37 CFR 1.27. Contains: 2 requirements, 1 prohibition, 5 guidance statements, 1 permission, and 3 other statements.

Key Rules

Topic

Asserting Small Entity Status

5 rules
StatutoryInformativeAlways
[mpep-509-03-a-9648ec9ece7460c10ec4124c]
Investigation Needed Before Asserting Small Entity Status
Note:
An inventor must complete an investigation before claiming small entity status, even if paying the basic filing fee.

The assertion of small entity status (e.g., even by mere payment of the exact small entity basic filing fee) is not appropriate until such an investigation has been completed. For example, where there are three pro se inventors, before one of the inventors pays the small entity basic filing, basic national, or individual designation fee to establish small entity status, the single inventor asserting entitlement to small entity status should check with the other two inventors to determine whether small entity status is appropriate.

Jump to MPEP SourceAsserting Small Entity StatusEntity Status Certification RequirementsSmall Entity Status
StatutoryRecommendedAlways
[mpep-509-03-a-1a384a189c81ddeba5110118]
Assertion of Small Entity Status Required for Fee Reductions
Note:
Applicants must affirmatively assert small entity status by checking the appropriate box on the transmittal form, but may opt to file as a non-small entity if investigations are too costly.

Furthermore, once status as a small entity has been established in an application, a new determination of entitlement to small entity status is needed in the application or patent (1) when the issue fee is due and (2) when any maintenance fee is due. If an ex parte reexamination is requested for a patent, the requester must affirmatively state in the reexamination request that it is entitled to small entity in order for a requester to pay the small entity filing fees. For example, requester can affirmatively assert small entity status by checking the appropriate box in line 3 on the transmittal form (PTO/SB/57). It should be appreciated that the costs incurred in appropriately conducting the initial and subsequent investigations may outweigh the benefit of claiming small entity status. For some applicants it may be desirable to file as a non-small entity (by not filing a written assertion of small entity status and by submitting non-small entity fees) rather than undertaking the appropriate investigations which may be both difficult and time-consuming and which may be cost effective only where several applications are involved.

Jump to MPEP SourceAsserting Small Entity StatusThird Party RequesterIssue Fee Amount
StatutoryPermittedAlways
[mpep-509-03-a-29d1d10e505470acc2a17499]
Person Making Assertion Must Know Facts About Eligibility
Note:
The person claiming small entity status must thoroughly investigate and be knowledgeable about the circumstances that determine eligibility for such status.

The intent of 37 CFR 1.27 is that the person making the assertion of entitlement to small entity status is the person in a position to know the facts about whether or not status as a small entity can be properly established. That person, thus, has a duty to investigate the circumstances surrounding entitlement to small entity status to the fullest extent. It is important to note that small entity status must not be claimed unless the person or persons can unequivocally make the required self-certification.

Jump to MPEP Source · 37 CFR 1.27Asserting Small Entity StatusSmall Entity DefinitionEntity Status Certification Requirements
StatutoryRequiredAlways
[mpep-509-03-a-bd5c8790593729f8800e5a80]
Assertion Required for Small Entity Status
Note:
Individuals must file an assertion to claim small entity status, certifying their entitlement.

In view of the intent expressed during Congressional consideration of the legislation, it would be inappropriate for the U.S. Patent and Trademark Office to give advisory opinions as to entitlement to small entity status. Accordingly, any individual seeking to establish status as a small entity for purposes of paying the fee in an application or patent must file the assertion required by 37 CFR 1.27 and in so doing is self-certifying entitlement to small entity status.

Jump to MPEP Source · 37 CFR 1.27Asserting Small Entity StatusEntity Status Certification RequirementsSmall Entity Status
StatutoryInformativeAlways
[mpep-509-03-a-111b92fffb544c8072ca3540]
Payment of Small Entity Fee Invokes Self-Certification
Note:
A payment of a small entity basic filing, national, or individual designation fee activates the self-certification requirement without needing a specific written assertion.

Consistent with 37 CFR 1.4(d)(4), the payment of a small entity basic filing or national fee constitutes a certification under 37 CFR 11.18(b). Thus, a simple payment of the small entity basic filing, basic national, or individual designation fee, without a specific written assertion, activates the provisions of 37 CFR 1.4(d)(4) and, by that, invokes the self-certification requirement set forth in 37 CFR 11.18(b), regardless of whether the party is a practitioner or non-practitioner.

Jump to MPEP Source · 37 CFR 1.4(d)(4)Asserting Small Entity StatusEntity Status Certification RequirementsSmall Entity Status
Topic

Small Entity Status

3 rules
StatutoryRecommendedAlways
[mpep-509-03-a-2d9c2a5fcad1d3522c2b0275]
Check With Other Inventors Before Asserting Small Entity Status
Note:
Before one pro se inventor asserts small entity status, they must check with the other two inventors to ensure it is appropriate.

The assertion of small entity status (e.g., even by mere payment of the exact small entity basic filing fee) is not appropriate until such an investigation has been completed. For example, where there are three pro se inventors, before one of the inventors pays the small entity basic filing, basic national, or individual designation fee to establish small entity status, the single inventor asserting entitlement to small entity status should check with the other two inventors to determine whether small entity status is appropriate.

Jump to MPEP SourceSmall Entity StatusMaintenance Fee AmountsEntity Status (Small and Micro)
StatutoryInformativeAlways
[mpep-509-03-a-190269352c13214e510d3827]
U.S. Patent Office Does Not Provide Advisory Opinions on Small Entity Status
Note:
The U.S. Patent and Trademark Office does not offer opinions on whether individuals or organizations qualify as small entities for fee reductions.

The U.S. Patent and Trademark Office does not give advisory opinions as to whether or not a specific individual or organization qualifies as a small entity. In establishing reduced fees for persons, small business concerns, and nonprofit organizations, the Congressional consideration of the legislation which became Public Law 97-247 indicated an intent that the U.S. Patent and Trademark Office rely exclusively on a self-certification that a patent applicant qualifies as an independent inventor (now person), small business concern, or nonprofit organization. In addition, it was also stated during Congressional consideration of the legislation that no additional resources would be required to administer the system whereby fees would be reduced for small entities.

Jump to MPEP SourceSmall Entity StatusEntity Status (Small and Micro)Entity Status Certification Requirements
StatutoryInformativeAlways
[mpep-509-03-a-b2688971a555a0c2b1ce228e]
U.S. Patent Office Cannot Provide Advisory Opinions on Small Entity Status
Note:
The U.S. Patent and Trademark Office may not issue advisory opinions regarding eligibility for small entity status; applicants must self-certify their status.

In view of the intent expressed during Congressional consideration of the legislation, it would be inappropriate for the U.S. Patent and Trademark Office to give advisory opinions as to entitlement to small entity status. Accordingly, any individual seeking to establish status as a small entity for purposes of paying the fee in an application or patent must file the assertion required by 37 CFR 1.27 and in so doing is self-certifying entitlement to small entity status.

Jump to MPEP Source · 37 CFR 1.27Small Entity StatusEntity Status (Small and Micro)Entity Status Certification Requirements
Topic

Small Entity Definition

3 rules
StatutoryRecommendedAlways
[mpep-509-03-a-38ebd103dfe5501b9f23ec8f]
Review for Small Business Concern Status
Note:
Analyze whether the business meets the size standards defined by the Small Business Act to claim small entity status.

If small entity status is desired on the basis that the entity is a small business concern, the investigation should include a review of whether the business is a small business concern as defined by section 3 of the Small Business Act (Public Law 85-536 as amended by Public Law 106-50). Review of whether the business concern meets the size standards set forth in 13 CFR 121.801 through 121.805 to be eligible for reduced patent fees is also appropriate. Additionally, if the business has assigned, granted, conveyed or licensed (or is under an obligation to do so) any rights in the invention to others directly or indirectly, the same review for each other entity would also be appropriate.

Jump to MPEP SourceSmall Entity DefinitionSmall Entity StatusEntity Status (Small and Micro)
StatutoryProhibitedAlways
[mpep-509-03-a-d232a6a04467b448cb3e9412]
Investigation Required for Small Entity Status Claim
Note:
The person claiming small entity status must thoroughly investigate the circumstances and can only claim it if they can unequivocally self-certify.

The intent of 37 CFR 1.27 is that the person making the assertion of entitlement to small entity status is the person in a position to know the facts about whether or not status as a small entity can be properly established. That person, thus, has a duty to investigate the circumstances surrounding entitlement to small entity status to the fullest extent. It is important to note that small entity status must not be claimed unless the person or persons can unequivocally make the required self-certification.

Jump to MPEP Source · 37 CFR 1.27Small Entity DefinitionEntity Status Certification RequirementsSmall Entity Status
StatutoryRequiredAlways
[mpep-509-03-a-4bdd0a998d0b4d8ff587fc20]
U.S. Patent and Trademark Office Relies on Self-Certification for Small Entity Status
Note:
The U.S. Patent and Trademark Office requires patent applicants to self-certify their status as an independent inventor, small business concern, or nonprofit organization for reduced fees, with no additional resources needed for administration.

The U.S. Patent and Trademark Office does not give advisory opinions as to whether or not a specific individual or organization qualifies as a small entity. In establishing reduced fees for persons, small business concerns, and nonprofit organizations, the Congressional consideration of the legislation which became Public Law 97-247 indicated an intent that the U.S. Patent and Trademark Office rely exclusively on a self-certification that a patent applicant qualifies as an independent inventor (now person), small business concern, or nonprofit organization. In addition, it was also stated during Congressional consideration of the legislation that no additional resources would be required to administer the system whereby fees would be reduced for small entities.

Jump to MPEP SourceSmall Entity DefinitionEntity Status Certification RequirementsEntity Status (Small and Micro)
Topic

Entity Status (Small and Micro)

2 rules
StatutoryRecommendedAlways
[mpep-509-03-a-1400dc83193bc77de2e8c628]
Investigate Before Claiming Small Entity Status
Note:
Applicants must thoroughly investigate all facts and circumstances before claiming small entity status.

While small entity status is not difficult to obtain, it should be clearly understood that applicants need to do a complete and thorough investigation of all facts and circumstances before making a determination of actual entitlement to small entity status. 37 CFR 1.27(f). Where entitlement to small entity status is uncertain, it should not be claimed.

Jump to MPEP Source · 37 CFR 1.27(f)Entity Status (Small and Micro)Entity Status Certification RequirementsSmall Entity Status
StatutoryRecommendedAlways
[mpep-509-03-a-6f88405b97e2d2bdac150bf1]
Claiming Small Entity Status When Uncertain Is Prohibited
Note:
Applicants must not claim small entity status if it is uncertain, requiring a thorough investigation of all facts and circumstances.

While small entity status is not difficult to obtain, it should be clearly understood that applicants need to do a complete and thorough investigation of all facts and circumstances before making a determination of actual entitlement to small entity status. 37 CFR 1.27(f). Where entitlement to small entity status is uncertain, it should not be claimed.

Jump to MPEP Source · 37 CFR 1.27(f)Entity Status (Small and Micro)Entity Status Certification RequirementsSmall Entity Status
Topic

Entity Status Certification Requirements

1 rules
StatutoryInformativeAlways
[mpep-509-03-a-a6414a8923c559a02513a2db]
Investigate Before Claiming Small Entity Status
Note:
Applicants must thoroughly investigate all facts and circumstances before claiming small entity status; uncertainty should not lead to a claim.

While small entity status is not difficult to obtain, it should be clearly understood that applicants need to do a complete and thorough investigation of all facts and circumstances before making a determination of actual entitlement to small entity status. 37 CFR 1.27(f). Where entitlement to small entity status is uncertain, it should not be claimed.

Jump to MPEP Source · 37 CFR 1.27(f)Entity Status Certification RequirementsEntity Status (Small and Micro)Small Entity Status
Topic

Effect of Licenses on Entity Status

1 rules
StatutoryInformativeAlways
[mpep-509-03-a-a17cf670f52f52d2f9f24893]
Review for Small Business Eligibility and License Transfers
Note:
The rule requires reviewing size standards and license transfers to determine eligibility for reduced patent fees.

If small entity status is desired on the basis that the entity is a small business concern, the investigation should include a review of whether the business is a small business concern as defined by section 3 of the Small Business Act (Public Law 85-536 as amended by Public Law 106-50). Review of whether the business concern meets the size standards set forth in 13 CFR 121.801 through 121.805 to be eligible for reduced patent fees is also appropriate. Additionally, if the business has assigned, granted, conveyed or licensed (or is under an obligation to do so) any rights in the invention to others directly or indirectly, the same review for each other entity would also be appropriate.

Jump to MPEP SourceEffect of Licenses on Entity StatusPatent EligibilityEntity Status Certification Requirements
Topic

Reexamination Filing Fee

1 rules
StatutoryInformativeAlways
[mpep-509-03-a-6e3dfac5af03891fba175a62]
Small Entity Status Must Be Reaffirmed for Fees and Reexamination
Note:
The small entity status must be reaffirmed when issue fees or maintenance fees are due, and explicitly stated in a reexamination request.

Furthermore, once status as a small entity has been established in an application, a new determination of entitlement to small entity status is needed in the application or patent (1) when the issue fee is due and (2) when any maintenance fee is due. If an ex parte reexamination is requested for a patent, the requester must affirmatively state in the reexamination request that it is entitled to small entity in order for a requester to pay the small entity filing fees. For example, requester can affirmatively assert small entity status by checking the appropriate box in line 3 on the transmittal form (PTO/SB/57). It should be appreciated that the costs incurred in appropriately conducting the initial and subsequent investigations may outweigh the benefit of claiming small entity status. For some applicants it may be desirable to file as a non-small entity (by not filing a written assertion of small entity status and by submitting non-small entity fees) rather than undertaking the appropriate investigations which may be both difficult and time-consuming and which may be cost effective only where several applications are involved.

Jump to MPEP SourceReexamination Filing FeeIssue Fee AmountSmall Entity Status
Topic

Third Party Requester

1 rules
StatutoryRequiredAlways
[mpep-509-03-a-4e2e552734d7432b774553ec]
Ex Parte Reexamination Request Must Assert Small Entity Status
Note:
The requester of an ex parte reexamination must affirmatively state in the request that they are entitled to small entity status to pay small entity filing fees.

Furthermore, once status as a small entity has been established in an application, a new determination of entitlement to small entity status is needed in the application or patent (1) when the issue fee is due and (2) when any maintenance fee is due. If an ex parte reexamination is requested for a patent, the requester must affirmatively state in the reexamination request that it is entitled to small entity in order for a requester to pay the small entity filing fees. For example, requester can affirmatively assert small entity status by checking the appropriate box in line 3 on the transmittal form (PTO/SB/57). It should be appreciated that the costs incurred in appropriately conducting the initial and subsequent investigations may outweigh the benefit of claiming small entity status. For some applicants it may be desirable to file as a non-small entity (by not filing a written assertion of small entity status and by submitting non-small entity fees) rather than undertaking the appropriate investigations which may be both difficult and time-consuming and which may be cost effective only where several applications are involved.

Jump to MPEP SourceThird Party RequesterIssue Fee AmountSmall Entity Status

Citations

Primary topicCitation
Asserting Small Entity Status
Small Entity Definition
Small Entity Status
37 CFR § 1.27
Entity Status (Small and Micro)
Entity Status Certification Requirements
37 CFR § 1.27(f)
Asserting Small Entity Status37 CFR § 1.4(d)(4)
Asserting Small Entity Status37 CFR § 11.18(b)

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