How to File a 35 USC 111(a) Patent Application

To file a nonprovisional patent application under 35 U.S.C. 111(a), you submit three things to the USPTO: a written specification describing your invention, any drawings needed to understand it, and an oath or declaration signed by each inventor.{¹} You also pay the filing, search, and examination fees. The specification alone is enough to secure your filing date, but the claims, oath, and fees must follow within the period the USPTO sets or your application will be treated as abandoned.

What Secures Your Filing Date

Your filing date sets your priority against every other applicant chasing the same invention. Under the first-inventor-to-file system that took effect in March 2013, a single day can decide who gets the patent.{²}

The statute is unusually forgiving about what has to arrive on day one. For a nonprovisional utility application, the filing date is the date the USPTO receives your specification. Claims and drawings are not required to establish that date, though they must be submitted within the period the office prescribes.{³} Miss that period, along with the oath and fees, and the application is abandoned.{¹}

Design patent applications work differently. A design filing needs the specification, at least one claim, and any required drawings all present on the filing date itself.{³}

Where and How to Submit

You can file electronically through the USPTO’s Patent Center, by U.S. mail, or by hand delivery to the USPTO office in Alexandria, Virginia.{⁴} Electronic filing is strongly preferred. Paper filings trigger a non-electronic filing surcharge of $400 for large entities, $200 for small entities, and $200 for micro entities on top of the standard fees.{⁵}

The application must identify each inventor’s full legal name and provide a correspondence address for official USPTO communications. If someone other than the inventor files, such as an assignee or legal representative, documentation must establish that person’s authority. Inaccurate contact information is a common cause of missed office actions, and missed office actions lead to abandonment.

Drafting the Specification

The specification is the written core of the application. Under 35 U.S.C. 112(a), it must describe the invention clearly enough that someone skilled in the relevant field could make and use it without excessive experimentation.{⁶} A typical specification includes a title, a background section, a summary, a detailed description, and examples or embodiments.

Section 112(a) sets three distinct requirements the specification must meet:{⁷}

Written description. The disclosure must show you possessed the invention at the time of filing. Aspirational language does not qualify.
Enablement. The description must let another practitioner reproduce the invention without guesswork at critical steps.
Best mode. You must disclose the best way you knew of to carry out the invention at the time of filing. This is a subjective standard tied to what the inventor actually knew.{} The America Invents Act removed best mode as a basis for invalidating an issued patent, but it remains a filing requirement.⁸

If your invention involves nucleotide or amino acid sequences, an electronic sequence listing in WIPO Standard ST.26 format is required for any application filed on or after July 1, 2022, including continuations and divisionals whose parent used the older ST.25 format.{⁹}

Writing the Claims

Claims define the legal boundary of the patent. They control what others can and cannot make, use, or sell. Every application must include at least one claim, and 35 U.S.C. 112(b) requires each claim to distinctly identify what the inventor regards as the invention.{¹⁰}

Claims come in two varieties. Independent claims stand on their own and describe the invention broadly. Dependent claims reference an independent claim and add narrowing limitations. Each claim must be a single sentence, which is one reason complex inventions are hard to claim well. Draft too broadly and the examiner will reject the claim as overlapping with existing inventions. Draft too narrowly and competitors have room to design around the patent.

Claims must be fully supported by the specification. If a claim describes a feature the specification never discusses, the examiner will reject it. Specification and claims need to be drafted together, not in isolation.

Drawings

Drawings are required whenever they are necessary to understand the invention. The statute gives the USPTO Director authority to require them when the subject matter can be illustrated and the applicant has not provided them.{¹¹} Nearly every mechanical, electrical, and design application includes drawings. Chemical and software inventions sometimes use flowcharts or reaction diagrams instead.

Black-and-white line drawings using India ink or an equivalent are the default. Color drawings are routinely allowed in design applications but only rarely permitted in utility applications, and only after a petition explaining why color is the sole practical way to disclose the invention.{¹²} Drawings that fail the USPTO’s rules on line thickness, shading, and numbering will draw a notice requiring corrected versions.

The Inventor’s Oath or Declaration

Every named inventor must execute an oath or declaration confirming that the application was made or authorized by them and that they believe they are the original inventor or a joint inventor of the claimed invention.{¹³} The document must also acknowledge that willful false statements are punishable under federal law by a fine, up to five years in prison, or both.{¹⁴}

The oath does not have to be filed with the specification. It can arrive later, but if it is not received within the prescribed period along with the fees and claims, the application is abandoned.{¹}

When an Inventor Cannot Sign

If an inventor is deceased, legally incapacitated, refuses to cooperate, or cannot be located after a diligent search, another person may file a substitute statement in place of the oath.{¹⁵} The person filing must identify which circumstance applies, confirm they have reviewed the entire application including the claims, and acknowledge the duty to disclose information material to patentability.

The Duty of Candor and the IDS

Every inventor, attorney, and other person substantively involved in prosecuting the application has a duty to disclose information that bears on whether the patent should be granted. Under 37 CFR 1.56, information is material if it undermines a claim’s patentability or contradicts a position taken before the USPTO.{¹⁶} Bad-faith or intentional violations can lead the USPTO to refuse the patent, and courts can hold an issued patent unenforceable for inequitable conduct.

The practical way to meet this duty is by filing an Information Disclosure Statement listing prior art and other references you know of that relate to patentability. Timing controls the cost. An IDS filed within three months of the filing date, or before the first office action on the merits, is considered without any additional fee or statement.{¹⁷} After that window but before a final action or notice of allowance, the USPTO will still consider the IDS if you pay an additional fee or provide a certification statement. After a notice of allowance, both are required. Once the issue fee is paid, there is no mechanism to have an IDS considered at all.

Fees by Entity Status

Every nonprovisional application requires a filing fee, a search fee, and an examination fee. What you pay depends on your entity status. Large entities pay the full amount, small entities receive a 60% discount, and micro entities receive an 80% discount.{¹⁸}

Combined fees for a utility application filed electronically:{⁵}

Large entity: $350 filing + $770 search + $880 examination = $2,000
Small entity: $140 filing + $308 search + $352 examination = $800
Micro entity: $70 filing + $154 search + $176 examination = $400

Small entities that file electronically can qualify for a reduced basic filing fee of $70, which brings the small entity total down to $730. These figures do not include excess claim fees, application size fees, or the paper filing surcharge.

Professional drafting is a separate cost. Patent attorney fees for a utility application typically range from roughly $5,000 to $15,000 or more depending on complexity. Simple mechanical devices sit at the lower end, while software, biotech, and semiconductor inventions push toward the high end.

Prioritized Examination (Track One)

If speed matters, the USPTO’s Track One program can produce a final decision within roughly 12 months rather than the typical two to three years. The prioritized examination fee is $4,515 for large entities, $1,806 for small entities, and $903 for micro entities, on top of the standard fees.{⁵} All fees and application components must be filed together on the filing date, and the application must be electronic.{¹⁹}

How This Differs From a Provisional Application

Section 111(a) covers nonprovisional applications, the kind that are examined and can issue as patents. Section 111(b) covers provisional applications, which are a lighter placeholder. A provisional requires only a specification and any necessary drawings. No claims, no oath, and no examination. It secures a filing date and lets you use “patent pending” for 12 months. It will never become a patent on its own, and it cannot claim priority from an earlier application. If you do not file a corresponding nonprovisional under 111(a) within 12 months, the provisional is automatically abandoned and cannot be revived.{¹}

Before Filing Abroad

If the invention was made in the United States, you generally cannot file a patent application in a foreign country until six months after your U.S. filing, unless you first obtain a foreign filing license from the USPTO.{²⁰} The USPTO routinely grants these licenses, and one is typically included on your filing receipt. Filing abroad without proper authorization can cost you the right to a U.S. patent on that invention.

After Filing: Responding and Avoiding Abandonment

Applications are rarely allowed on the first review. Examiners issue office actions identifying problems, and applicants respond with amendments. Most office actions carry a three-month response deadline extendable to six months total by paying extension fees. Miss the six-month outer deadline and the application goes abandoned.

Amendments have one hard rule: no new matter.{²¹} Every change must be supported by what was already in the original specification. Anything not disclosed at filing cannot be added later by amendment. If you need to add material the original disclosure does not support, a continuation-in-part application is the proper vehicle, and the new material gets its own filing date.

If an application is abandoned unintentionally, a petition to revive under 37 CFR 1.137 is available. It requires the overdue response, a petition fee, and a statement that the entire delay was unintentional.{²²} The petition fee alone runs $1,700 for large entities. Filing within six months of abandonment tends to go smoothly; long delays invite scrutiny and can be denied.

1
Office of the Law Revision Counsel. 35 U.S.C. 111 – Application
2
United States Patent and Trademark Office. First Inventor to File (FITF) Resources
3
United States Patent and Trademark Office. Manual of Patent Examining Procedure – 702 Requisites of the Application
4
United States Patent and Trademark Office. Nonprovisional Utility Patent Application Filing Guide
5
United States Patent and Trademark Office. USPTO Fee Schedule
6
Office of the Law Revision Counsel. 35 U.S.C. 112 – Specification
7
United States Patent and Trademark Office. Manual of Patent Examining Procedure – 2161 Three Separate Requirements for Specification Under 35 U.S.C. 112(a)
8
United States Patent and Trademark Office. Manual of Patent Examining Procedure – 2165 The Best Mode Requirement
9
United States Patent and Trademark Office. WIPO Standard ST.26 News
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United States Patent and Trademark Office. Manual of Patent Examining Procedure – 2173 Claims Must Particularly Point Out and Distinctly Claim the Invention
11
GovInfo. 35 U.S.C. 113 – Drawings
12
eCFR. 37 CFR 1.84 – Standards for Drawings
13
Office of the Law Revision Counsel. 35 U.S.C. 115 – Inventor’s Oath or Declaration
14
eCFR. 37 CFR 1.63 – Inventor’s Oath or Declaration
15
United States Patent and Trademark Office. Manual of Patent Examining Procedure – 604 Substitute Statements
16
eCFR. 37 CFR 1.56 – Duty to Disclose Information Material to Patentability
17
United States Patent and Trademark Office. Manual of Patent Examining Procedure – 609 Information Disclosure Statement
18
United States Patent and Trademark Office. Save on Fees With Small and Micro Entity Status
19
United States Patent and Trademark Office. Prioritized Examination, Track One
20
United States Patent and Trademark Office. Manual of Patent Examining Procedure – 140 Foreign Filing Licenses
21
GovInfo. 35 U.S.C. 132 – Notice of Rejection; Reexamination
22
eCFR. 37 CFR 1.137 – Revival of Abandoned Application, Terminated or Limited Reexamination Prosecution, or Lapsed Patent