A Guide to Filing a

Utility Patent Application
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

i

A Guide to Filing a

Utility Patent Application

■ Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

■ Nonprovisional Utility Patent Application Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

■ Utility Patent Application Transmittal Form Or Transmittal Letter Fee

Transmittal Form And Appropriate Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Application Data Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

■ Title Of Invention. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

■ Cross-Reference To Related Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

■ Statement Regarding Federally Sponsored Research Or Development . . . . . . . . . . . . . . . 4 

■ Reference To A Sequence Listing, A Table, Or A Computer Program Listing

Compact Disc Appendix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

■ Background Of The Invention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

■ Brief Summary Of The Invention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

■ Brief Description Of The Several Views Of The Drawing. . . . . . . . . . . . . . . . . . . . . . . . . 5 

■ Detailed Description Of The Invention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

■ Claim Or Claims . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

■ Abstract Of The Disclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Drawings (When Necessary) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Oath Or Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Sequence Listing (When Necessary) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

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■ Obtaining A Receipt For Documents Mailed To The USPTO . . . . . . . . . . . . . . . . . . . . . . . . . . 7

■ Drawing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Identification Of Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Graphic Forms In Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

Paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

■ Exploded Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

■ Partial Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

■ Sectional Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

■ Alternate Position. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

■ Modified Forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Arrangement Of Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Front Page View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Character Of Lines, Numbers, And Letters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Shading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Legends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Numbers, Letters, And Reference Characters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Lead Lines And Arrows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Copyright Or Mask Work Notice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Numbering Of Sheets Of Drawings And Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Security Markings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

■ Patent and Trademark Depository Library (PTDL) Program . . . . . . . . . . . . . . . . . . . . . . . . . . 13 
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

The United States Patent and Trademark Office

(USPTO or Office) is the government agency

responsible for examining patent applications

and issuing patents. A patent is a type of property right.

It gives the patent holder the right, for a limited time,

to exclude others from making, using, offering to sell,

selling, or importing into the United States the subject

matter that is within the scope of protection granted by

the patent. The USPTO determines whether a patent

should be granted in a particular case. However, it is

up to the patent holder to enforce his or her own rights

if the USPTO does grant a patent. 

The purpose of this guide is to provide you with basic

information about filing a utility patent application.

A patent application is a complex legal document,

best prepared by one trained to prepare such

documents. Thus, after reviewing this guide, you

may wish to consult with a registered patent attorney

or agent. Additional information is available: 

■ by calling the USPTO's General Information

Services Division at 800-PTO-9199 or

703-308-4357, 

■ from the USPTO's Web site at www.uspto.gov,

and 

■ at your nearest Patent and Trademark

Depository Library (PTDL). You will find

information on PTDLs at the end of this guide. 

There are various types of patents -- utility, design,

and plant. There are also two types of utility and

plant patent applications -- provisional and

nonprovisional. Each year the USPTO receives

approximately 300,000 patent applications. Most of

these are for nonprovisional utility patents. 

This guide contains information to assist you in filing

your nonprovisional utility patent application. It

discusses the required parts of the utility patent

application and identifies some of the forms you may

use (which are available on the USPTO's Web site

www.uspto.gov). This information is generally

derived from patent laws and regulations, found at

Title 35 of the United States Code (U.S.C.), and Title

37 of the Code of Federal Regulations (CFR). These

materials, as well as the Manual of Patent Examining

Procedure, are available at the USPTO's Web site

(www.uspto.gov), PTDLs, and at most law libraries. 

If you have questions about: 

■ other types of patent applications, 

■ locating a patent attorney or agent, 

■ obtaining the most up-to-date Fee Schedule, or 

■ obtaining copies of other USPTO publications, 

please contact General Information Services

Division, the USPTO’s Web site, or a PTDL. 

1

INTRODUCTION
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

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Anonprovisional utility patent application

must be in the English language or be

accompanied by a verified translation in the

English language and a fee set forth in 37 CFR

§1.17(i) [Non-English Specification Fee Code 139]. 

All papers which are to become part of the permanent

records of the USPTO must be typewritten or

produced by a mechanical (or computer) printer. The

text must be in permanent black ink or its equivalent;

on a single side of the paper; in portrait orientation;

on white paper that is all of the same size, flexible,

strong, smooth, nonshiny, durable, and without holes.

The paper size must be either: 

■ 21.6 cm. by 27.9 cm. (81/2 by 11 inches), or 

■ 21.0 cm. by 29.7 cm. (DIN size A4). 

There must be a left margin of at least 2.5 cm. (1

inch) and top, right, and bottom margins of at least

2.0 cm. (3/4 inch). Drawing page requirements are

discussed separately below. 

A nonprovisional utility patent application must

include a specification, including a claim or claims;

drawings, when necessary; an oath or declaration;

and the prescribed filing fee. A complete

nonprovisional utility patent application should

contain the elements listed below, arranged in the

order shown. 

■ Utility Patent Application Transmittal Form or

Transmittal Letter 

■ Fee Transmittal Form and Appropriate Fee 

■ Application Data Sheet (see 37 CFR § 1.76)

■ Specification (with at least one claim)

■ Drawings (when necessary) 

■ Oath or Declaration 

■ Nucleotide and/or Amino Acid Sequence Listing

(when necessary) 

These elements are further described as follows: 

NONPROVISIONAL UTILITY PATENT

APPLICATION REQUIREMENTS 
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

AUtility Patent Application Transmittal Form

(Form PTO/SB/05) or a transmittal letter

should be filed with every patent application

to instruct the USPTO as to what actual types of

papers are being filed (e.g., specification, claims

drawings, declaration, information disclosure

statement). It identifies the name of the applicant,

the type of application, the title of the invention, the

contents of the application, and any accompanying

enclosures. (Form PTO/SB/21 is to be used for all

correspondence after initial filing.) 

Fee Transmittal Form

and Appropriate Fee

The Fee Transmittal Form (Form PTO/SB/17) may be

used to calculate the prescribed filing fees and indicate

the method of payment, by check or by credit card.

The amount and type of filing fees are dependent upon

the number and type of claims presented. 

The filing fee(s) for a patent application should be

submitted with the application and must be made

payable to the "Commissioner of Patents and

Trademarks" if paid by check. If an application is filed

without the basic filing fee, the applicant will be

notified and will be required to submit the filing fee

along with a surcharge within the time period set in the

notice. Fees are subject to change and the applicant

should consult the current Fee Schedule before filing. 

Please note that two sets of fees exist, one for small

entities and one for other than small entities. If you

qualify as a small entity for patent fee purposes, no

special form is required to claim your entitlement to

reduced fees (you may check a special box on the

transmittal form), but you should only pay small

entity rates after ensuring that you qualify for the

small entity discount. For example, if the inventors

have not assigned any rights in the invention set forth

in the application and are not under any obligation to

do so (as may be required in an employment

contract), small entity status is appropriate.

Application Data Sheet

The application data sheet is a sheet or sheets, that may

be voluntarily submitted in either provisional or

nonprovisional applications, which contains bibliographic

data, arranged in a format specified by the USPTO.

Specific bibliographic data includes applicant

information, correspondence information, application

information, representative information, domestic priority

information, foreign priority information and assignment

information. (See 37 CFR § 1.76.) The sheets must be

produced according to a format provided by the USPTO

and which is downloadable to applicant’s computer.

Supplemental application data sheets may be

subsequently supplied prior to payment of issue fee to

either correct or update information in a previously

submitted application data sheet, or an oath or declaration

under title 37 CFR § 1.63 or 1.67. However, inventorship

changes are governed by 37 CFR § 1.48, correspondence

changes are governed by 37 CFR § 1.33(a), and

citizenship changes are governed by 37 CFR § 1.63

or 1.67. Supplemental application data sheets should

indicate the information that is being supplemented, and

therefore need not and should not contain information

previously supplied that has not changed.

Specification

The specification is a written description of the

invention and of the manner and process of making

and using the same. The specification must be in

such full, clear, concise, and exact terms as to enable

any person skilled in the art or science to which the

invention pertains to make and use the same. 

3

UTILITY PATENT APPLICATION TRANSMITTAL FORM

OR TRANSMITTAL LETTER
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

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Computer program listings, when submitted as part of

the specification, must be direct printouts (not copies)

from the computer's printer with dark, solid black

letters not less than 0.21 cm. (0.08 inch) high (elite

type), on white, unshaded and unlined paper; and the

sheets should be submitted in a protective cover. The

pages of the specification (but not the transmittal

letter sheets or other forms), including claims and

abstract, should be numbered consecutively, starting

with 1. The page numbers should be centrally located

preferably below the text. The lines of the

specification must be 1.5 or double spaced (lines of

text not comprising the specification need not be 1.5

or double spaced). It is desirable to include an

indentation at the beginning of each new paragraph,

and for paragraphs to be numbered (0001 etc.). 

It is preferable to use all of the section headings

described below to represent the parts of the

specification. Section headings should be in upper

case without underlining or bold type. If the section

contains no text, the phrase "Not Applicable" should

follow the section heading. 

TITLE OF INVENTION

The title of the invention (or an introductory portion

stating the name, citizenship, residence of each

applicant, and the title of the invention) should appear

as the heading on the first page of the specification.

Although a title may have up to 500 characters, the

title must be as short and specific as possible. 

CROSS-REFERENCE TO RELATED

APPLICATIONS 

Any nonprovisional utility patent application claiming

the benefit of one or more prior filed copending

nonprovisional applications (or international

applications designating the United States of America)

under 35 USC §§ 120, 121 or 365(c) must contain in

the first sentence of the specification following the

title, a reference to each such prior application,

identifying it by the application number or

international application number and international

filing date, and indicating the relationship of the

applications, or include the reference to the earlier

application in an application data sheet. (See 37 CFR

§ 1.76.) Cross-references to other related patent

applications may be made when appropriate.

STATEMENT REGARDING FEDERALLY

SPONSORED RESEARCH OR DEVELOPMENT

The application should contain a statement as to

rights to inventions made under federally sponsored

research and development (if any). 

REFERENCE TO SEQUENCE LISTING, A

TABLE, OR A COMPUTER PROGRAM

LISTING COMPACT DISC APPENDIX 

Any material submitted separately on a compact disc

must be referenced in the specification. The only

disclosure material accepted on compact disc are

computer program listings, gene sequence listings and

tables of information. All such information submitted

on compact disc must be in compliance with 37 CFR §

1.52(e), and the specification must contain a reference

to the compact disc and its contents. The contents of

compact disc files must be in standard ASCII character

and file formats. The total number of compact discs

including duplicates and the files on each compact disc

must be specified.

If a computer program listing is to be submitted

and is over 300 lines long (each line of up to 72

characters), the computer program listing must be

submitted on a compact disc in compliance with 37

CFR § 1.96, and the specification must contain a

reference to the computer program listing

appendix. A computer program listing of 300 or

less lines may similarly be submitted on compact

disc. The computer program listing on compact

disc will not be printed with any patent or patent

application publication. 

If a gene sequence listing is to be submitted, the

sequence may be submitted on a compact disc in

compliance with 37 CFR §§ 1.821-1.825, in lieu of

submission on paper, and the specification must

contain a reference to the gene sequence listing on

compact disc.

If a table of data is to be submitted, and such table

would occupy more than 50 pages if submitted on

paper, the table can be submitted on a compact disc

in compliance with 37 CFR § 1.58, and the

specification must contain a reference to the table on

compact disc. The data in the table must properly

align visually with the associated rows and columns.
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

BACKGROUND OF THE INVENTION

This section should include a statement of the field of

endeavor to which the invention pertains. This

section may also include a paraphrasing of the

applicable U.S. patent Classification Definitions or

the subject matter of the claimed invention. In the

past, this part of this section may have been titled

"Field of Invention" or "Technical Field." 

This section should also contain a description of

information known to you, including references to

specific documents, which are related to your

invention. It should contain, if applicable, references

to specific problems involved in the prior art (or state

of technology) which your invention is drawn

toward. In the past, this section may have been titled

"Description of the Related Art" or "Description of

Prior Art." 

BRIEF SUMMARY OF THE INVENTION 

This section should present the substance or

general idea of the claimed invention in

summarized form. The summary may point out the

advantages of the invention and how it solves

previously existing problems, preferably those

problems identified in the BACKGROUND OF

THE INVENTION. A statement of the object of

the invention may also be included. 

BRIEF DESCRIPTION OF THE SEVERAL

VIEWS OF THE DRAWING

Where there are drawings, you must include a listing

of all figures by number (e.g., Figure 1A) and with

corresponding statements explaining what each

figure depicts. 

DETAILED DESCRIPTION

OF THE INVENTION 

In this section, the invention must be explained along

with the process of making and using the invention in

full, clear, concise, and exact terms. This section

should distinguish the invention from other

inventions and from what is old and describe

completely the process, machine, manufacture,

composition of matter, or improvement invented. In

the case of an improvement, the description should

be confined to the specific improvement and to the

parts that necessarily cooperate with it or which are

necessary to completely understand the invention. 

It is required that the description be sufficient so that

any person of ordinary skill in the pertinent art,

science, or area could make and use the invention

without extensive experimentation. The best mode

contemplated by you of carrying out your invention

must be set forth in the description. Each element in

the drawings should be mentioned in the description.

This section has often, in the past, been titled

"Description of the Preferred Embodiment." 

CLAIM or CLAIMS

The claim or claims must particularly point out and

distinctly claim the subject matter which you regard

as the invention. The claims define the scope of the

protection of the patent. Whether a patent will be

granted is determined, in large measure, by the

choice of wording of the claims. 

A nonprovisional application for a utility patent must

contain at least one claim. The claim or claims

section must begin on a separate sheet. If there are

several claims, they shall be numbered consecutively

in Arabic numerals, with the least restrictive claim

presented as claim number 1. 

The claims section must begin with a statement such

as "What I claim as my invention is: . . ." or "I (We)

claim: . . ." followed by the recitation of the

particular matter which you regard as your invention.

One or more claims may be presented in dependent

form, referring back to and further limiting another

claim or claims in the same application. All

dependent claims should be grouped together with

the claim or claims to which they refer to the extent

practicable. Any dependent claim that refers to more

than one other claim ("a multiple dependent claim")

shall refer to such other claims in the alternative only.

Each claim should be a single sentence, and where a

claim sets forth a number of elements or steps, each

element or step of the claim should be separated by a

line indentation. 

The fee required to be submitted with a

nonprovisional utility patent application is, in part,

determined by the number of claims, independent

claims, and dependent claims. 

5
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

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ABSTRACT OF THE DISCLOSURE

The purpose of the abstract is to enable the USPTO

and the public to determine quickly the nature of the

technical disclosures of your invention. The abstract

points out what is new in the art to which your

invention pertains. It should be in narrative form and

generally limited to a single paragraph, and it must

begin on a separate page. An abstract should not be

longer than 150 words. 

Drawings (when necessary)

A patent application is required to contain drawings

if drawings are necessary for the understanding of

the subject matter sought to be patented. The

drawings must show every feature of the invention

as specified in the claims. Omission of drawings

may cause an application to be considered

incomplete. Please see the detailed discussion of

drawing requirements. 

Oath Or Declaration

The oath or declaration (Forms PTO/SB/01,

PTO/SB/02A and PTO/SB/02B may be used) must

identify the application with which it is associated,

and must give the name, city, and either state or

country of residence, country of citizenship, and

mailing address of each inventor. It must state

whether the inventor is a sole or joint inventor of the

invention claimed. Additionally, designation of a

correspondence address is needed on the oath or

declaration. Providing a correspondence address will

help to ensure prompt delivery of all notices, official

letters, and other communications. In addition, a

shortened declaration may be used in conjuction with

an Application Data Sheet (see Form PTO/SB/01A).

The oath or declaration must be signed by all of the

actual inventors. An oath may be administered by

any person within the United States, or by a

diplomatic or consular officer of a foreign country,

who is authorized by the United States to administer

oaths. A declaration does not require any witness or

person to administer or verify its signing. Thus, use

of a declaration is preferable. 

The oath or declaration must be in a language which

you understand. If you comprehend the English

language, you should preferably use an English

language oath or declaration. If you cannot

comprehend English, any oath or declaration must be

in a language which you can comprehend and shall

state that you understand the content of any

documents to which the oath or declaration relates. If

the oath or declaration used is in a language other

than English, the oath or declaration must either be

(1) accompanied by a verified English translation, or

(2) in a form provided or approved by the United

States Patent and Trademark Office. 

If the person making the oath or declaration is not the

inventor, the oath or declaration shall state the

relationship of that person to the inventor, upon

information and belief, the facts which the inventor

would have been required to state, and the

circumstances which render the inventor unable to

sign, namely death, insanity or legal incapacity or

unavailability/refusal to sign. (See 37 CFR §§ 1.42,

1.43, and 1.47.) If the inventor has refused or cannot

be reached to sign the declaration, then a petition

under 37 CFR § 1.47 is required, and if there are

inventors who have signed the oath or declaration,

then the remaining inventors must sign the oath or

declaration on behalf of the non-signing inventor. If

the sole or all of the inventors has not signed the oath

or declaration, then the oath or declaration must be

signed by the party showing proprietary interest in

the application, as shown in the petition under 37

CFR § 1.47(b). If the inventor has died or is legally

incapacitated, then the legal representative of the

deceased or incapacitated inventor must sign the oath

or declaration on behalf of the inventor.

Sequence Listing (when necessary) 

This section, for the disclosure of a nucleotide and/or

amino acid sequence, should contain a listing of the

sequence complying with 37 CFR § 1.821 through 37

CFR § 1.825 and may be in paper or electronic form. 
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

Areceipt for documents mailed to the USPTO

can be obtained by attaching a stamped, selfaddressed postcard to the first page of the

documents. The postcard should contain a detailed list

that identifies each type of document and the number of

pages of each document. Upon receipt at the USPTO,

the detailed list on the postcard will be compared to the

actual contents of the delivery. Any discrepancies

between the detailed list and the actual contents will be

noted on the postcard. The postcard will be initialed and

date stamped by the person at the USPTO who received

the delivery. The postcard will be returned by mail to

the addressee whose name appears on the postcard. 

The returned postcard serves as evidence of receipt in

the USPTO of all items listed on the postcard, unless

otherwise noted by the USPTO on the postcard. That

is, if the postcard receipt has been annotated to

indicate that a particular paper was not received, the

postcard receipt will not serve as evidence of receipt of

that paper in the USPTO. Likewise, the postcard

receipt will not serve as evidence of receipt of papers

which are not adequately itemized. 

When preparing the detailed list of documents

identified on the postcard, it is important to include

the following identifying information: 

■ the application number (if known) 

■ the confirmation number (if known) 

■ the filing date of the application (if known) 

■ the title of the invention 

■ the name of the inventor or inventors. 

The postcard should also include a detailed list of

every document type and the number of pages of each

document that are included in the delivery. If the

postcard is submitted with a patent application, the

detailed listing should include the following items: 

■ the title and number of pages of each

USPTO form 

■ the number of pages of specification

(excluding claims) 

■ the number of claims and the number of

claim pages 

■ the number of figures of drawing and the

number of sheets of drawing 

■ whether an oath or declaration statement

is included and the number of pages

■ the type and number of other documents that

are included and the number of pages of

each document 

■ the amount of payment and the method of

payment (i.e., check, credit card, money order,

or deposit account). 

It is important that the postcard itemizes each component

of the application. For example, a general statement such

as "complete application" or "patent application" or

"drawings" will not show that each of the required

components of an application was included if one of the

items is later found to be missing by the USPTO. 

When the self-addressed postcard is submitted with a

utility patent application, the USPTO will stamp the

postcard being returned to the addressee with both

the receipt date and the application number before

placing it in the outgoing mail. 

Upon receipt of the returned postcard, the addressee

should promptly review the postcard to ensure that all

documents and all pages were received by the USPTO. 

Pursuant to 35 USC 21 and 37 CFR § 1.10, any

correspondence received by the USPTO (including

an application filing) that was delivered by the

“Express Mail Post Office to Addressee” service of

the United States Postal Service (USPS) will be

considered filed in the Office on the date of deposit

with the USPS. The date of deposit with the USPS is

shown by the “date-in” on the “Express Mail”

mailing label or other official USPS notation. If the

USPS deposit date cannot be determined, however,

the correspondence will be accorded the Office

receipt date as the filing date. Before depositing an

application with the USPS in accordance with the

Express Mail procedure set forth at 37 CFR § 1.10, it

is important to place the number of the “Express

Mail” mailing label on the application papers.

Further, only one application should be mailed in a

single “Express Mail” package.

7

OBTAINING A RECEIPT FOR DOCUMENTS

MAILED TO THE USPTO
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

8

I

nformation on drawing requirements is based

substantially on 37 CFR § 1.84. There are two

acceptable categories for presenting drawings in

utility patent applications: black ink (black and

white) and color. 

Black and white drawings are normally required.

India ink, or its equivalent that secures black solid

lines, must be used for drawings. Drawings made by

computer printer should be originals, not photocopies. 

On rare occasions, color drawings may be necessary

as the only practical medium by which the subject

matter sought to be patented in a utility patent

application is disclosed. The USPTO will accept color

drawings in utility patent applications and statutory

invention registrations only after granting a petition

explaining why the color drawings are necessary. Any

such petition must include the following: 

■ the appropriate fee set forth in 37 CFR §1.17(h) 

■ three sets of color drawings; and 

■ the following language as the first paragraph in

that portion of the specification relating to the

BRIEF DESCRIPTION OF THE SEVERAL

VIEWS OF THE DRAWING. If the language is

not in the specification, an amendment to insert

the language must accompany the petition. 

"The patent or application file contains at least one

drawing executed in color. Copies of this patent or

patent application publication with color drawing(s)

will be provided by the Office upon request and

payment of the necessary fee." 

Photographs are not ordinarily permitted in utility

patent applications. The USPTO will accept black

and white photographs in utility patent applications

only in applications in which the invention is not

capable of being illustrated in an ink drawing or

where the invention is shown more clearly in a

photograph. For example, photographs or

photomicrographs of electrophoresis gels, blots

(e.g., immunological, western, southern, and

northern), autoradiographs, cell cultures (stained

and unstained), histological tissue cross sections

(stained and unstained), animals, plants, in vivo

imaging, thin layer chromatography plates,

crystalline structures, and ornamental effects

continue to be acceptable. Only one set of black and

white photographs is required. Furthermore, no

additional processing fee is required. 

Photographs have the same sheet size requirements

as other drawings. The photographs must be of

sufficient quality so that all details in the drawing are

reproducible in the printed patent or any patent

application publication. 

Color photographs will be accepted in utility patent

applications if the conditions for accepting color

drawings have been satisfied. 

Identification of Drawings

Identifying indicia, if provided, should include the

title of the invention, the inventor's name, the

application number (if known), the confirmation

number (if known), and docket number (if any). This

information should be placed on the top margin of

each sheet of drawings, centered on the page. The

name and telephone number of a person to call if the

USPTO is unable to match the drawings to the proper

application may also be provided. 

DRAWING REQUIREMENTS
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

Graphic Forms in Drawings

Chemical or mathematical formulas, tables,

computer program listings, and waveforms may be

submitted as drawings and are subject to the same

requirements as drawings. Each chemical or

mathematical formula must be labeled as a separate

figure, using brackets when necessary, to show that

information is properly integrated. Each group of

waveforms must be presented as a single figure,

using a common vertical axis with time extending

along the horizontal axis. Each individual waveform

discussed in the specification must be identified with

a separate letter designation adjacent to the vertical

axis. These may be placed in a landscape orientation

if they cannot be presented satisfactorily in a portrait

orientation. Typewritten characters used in such

formulas and tables must be chosen from a block

(nonscript) type font or lettering style having capital

letters which are at least 0.21 cm. (0.08 inch) high

(elite type). A space at least 0.64 cm. (1/4 inch) high

should be provided between complex formulas or

tables and the text. 

Paper

Drawings submitted to the USPTO must be made on

paper which is flexible, strong, white, smooth,

nonshiny, and durable. All sheets must be free from

cracks, creases, and folds. Only one side of the sheet

shall be used for the drawing. Each sheet must be

reasonably free from erasures and must be free from

alterations, overwritings, and interlineations. 

All drawings sheets, including sheets containing

photographs, in an application must be the same size.

One of the shorter sides of the sheet is regarded as its

top. The size of the sheets on which drawings are

made must be: 

■ 21.6 cm. by 27.9 cm. (81/2 by 11 inches), or 

■ 21.0 cm. by 29.7 cm. (DIN size A4). 

The sheets must not contain frames around the sight

(the usable surface), but should have scan target

points (cross hairs) printed on two catercorner

margin corners. The following margins are required: 

■ On 21.6 cm. by 27.9 cm. (81/2 by 11 inch)

drawing sheets, each sheet must include a top

margin of at least 2.5 cm. (1 inch), a left side

margin of at least 2.5 cm. (1 inch), a right side

margin of at least 1.5 cm. (5/8 inch), and a

bottom margin of at least 1.0 cm. (3/8 inch)

from the edges, thereby leaving a sight no

greater than 17.6 cm. by 24.4 cm. (6 15/16 by

9 5/8 inches). 

■ On 21.0 cm. by 29.7 cm. (DIN size A4) drawing

sheets, each sheet must include a top margin of

at least 2.5 cm. (1 inch), a left side margin of at

least 2.5 cm. (1 inch), a right side margin of at

least 1.5 cm (5/8 inch), and a bottom margin of

at least 1.0 cm. (3/8 inch) from the edges,

thereby leaving a sight no greater than 17.0 cm.

by 26.2 cm. 

Views

The drawing must contain as many views as

necessary to show the invention. The views may be

plan, elevation, section, or perspective views.

Detailed views of portions of elements, on a larger

scale if necessary, may also be used. All views of the

drawing must be grouped together and arranged on

the sheet(s) without wasting space, preferably in an

upright position, clearly separated from one another,

and must not be included in the sheets containing the

specifications, claims, or abstract. Views must not be

connected by projection lines and must not contain

center lines. Waveforms of electrical signals may be

connected by dashed lines to show the relative timing

of the waveforms. 

EXPLODED VIEWS 

Exploded views, with the separated parts embraced

by a bracket, to show the relationship or order of

assembly of various parts are permissible. When an

exploded view is shown in a figure which is on the

same sheet as another figure, the exploded view

should be placed in brackets. 

PARTIAL VIEWS

When necessary, a view of a large machine or device

in its entirety may be broken into partial views on a

single sheet, or extended over several sheets if there

is no loss in facility of understanding the view.

Partial views drawn on separate sheets must always

9
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

10

be capable of being linked edge to edge so that no

partial view contains parts of another partial view. A

smaller scale view should be included showing the

whole formed by the partial views and indicating the

positions of the parts shown. When a portion of a

view is enlarged for magnification purposes, the

view and the enlarged view must each be labeled as

separate views. 

Where views on two or more sheets form, in effect, a

single complete view, the views on the several sheets

must be so arranged that the complete figure can be

assembled without concealing any part of any of the

views appearing on the various sheets. 

A very long view may be divided into several parts

placed one above the other on a single sheet.

However, the relationship between the different parts

must be clear and unambiguous. 

SECTIONAL VIEWS

The plane upon which a sectional view is taken should

be indicated on the view from which the section is cut

by a broken line. The ends of the broken line should be

designated by Arabic or Roman numerals

corresponding to the view number of the sectional

view, and should have arrows to indicate the direction

of sight. Hatching must be used to indicate section

portions of an object, and must be made by regularly

spaced oblique parallel lines spaced sufficiently apart

to enable the lines to be distinguished without

difficulty. Hatching should not impede the clear

reading of the reference characters and lead lines. If it

is not possible to place reference characters outside the

hatched area, the hatching may be broken off wherever

reference characters are inserted. Hatching must be at

a substantial angle to the surrounding axes or principal

lines, preferably 45°. 

A cross section must be set out and drawn to show all

of the materials as they are shown in the view from

which the cross section was taken. The parts in cross

section must show proper material(s) by hatching

with regularly spaced parallel oblique strokes; the

space between strokes being chosen on the basis of

the total area to be hatched. The various parts of a

cross section of the same item should be hatched in

the same manner and should accurately and

graphically indicate the nature of the material(s)

illustrated in cross section. 

The hatching of juxtaposed different elements must

be angled in a different way. In the case of large

areas, hatching may be confined to an edging drawn

around the entire inside of the outline of the area to

be hatched. Different types of hatching should have

different conventional meanings as regards the

nature of a material seen in cross section. 

ALTERNATE POSITION

A moved position may be shown by a broken line

superimposed upon a suitable view if this can be

done without crowding; otherwise, a separate view

must be used for this purpose. 

MODIFIED FORMS

Modified forms of construction must be shown in

separate views. 

Arrangement of Views

One view must not be placed upon another or within

the outline of another. All views on the same sheet

should stand in the same direction and, if possible,

stand so that they can be read with the sheet held in

an upright position. If views wider than the width of

the sheet are necessary for the clearest illustration of

the invention, the sheet may be turned on its side so

that the top of the sheet is on the right-hand side,

with the appropriate top margin used as the heading

space. Words must appear in a horizontal, left-toright fashion when the page is either upright or

turned so that the top becomes the right side, except

for graphs utilizing standard scientific convention to

denote the axis of abscissas (of X) and the axis of

ordinates (of Y). 

Front Page View 

One of the views should be suitable for inclusion on

the front page of the patent application publication

and patent as the illustration of the invention. 

Scale

The scale to which a drawing is made must be large

enough to show the mechanism without crowding
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

when the drawing is reduced in size to two-thirds in

reproduction. Indications such as "actual size" or

"scale 1/2" are not permitted on the drawings since

these lose their meaning with reproduction in a

different format. 

Character of Lines, Numbers,

and Letters 

All drawings must be made by a process which will

give them satisfactory reproduction characteristics.

Every line, number, and letter must be durable, clean,

black (except for color drawings), sufficiently dense

and dark, and uniformly thick and well-defined. The

weight of all lines and letters must be heavy enough

to permit adequate reproduction. This requirement

applies to all lines however fine, to shading, and to

lines representing cut surfaces in sectional views.

Lines and strokes of different thicknesses may be

used in the same drawing where different thicknesses

have a different meaning. 

Shading

The use of shading in views is encouraged if it aids in

understanding the invention and if it does not reduce

legibility. Shading is used to indicate the surface or

shape of spherical, cylindrical, and conical elements

of an object. Flat parts may also be lightly shaded.

Such shading is preferred in the case of parts shown

in perspective, but not for cross sections. See

discussion of sectional views above. Spaced lines for

shading are preferred. These lines must be thin, as few

in number as practicable, and they must contrast with

the rest of the drawings. As a substitute for shading,

heavy lines on the shade side of objects can be used

except where they superimpose on each other or

obscure reference characters. Light should come from

the upper left corner at an angle of 45°. Surface

delineations should preferably be shown by proper

shading. Solid black shading areas are not permitted,

except when used to represent bar graphs or color. 

Symbols

Graphical drawing symbols may be used for

conventional elements when appropriate. The

elements for which such symbols and labeled

representations are used must be adequately

identified in the specification. Known devices should

be illustrated by symbols which have a universally

recognized conventional meaning and are generally

accepted in the art. Other symbols which are not

universally recognized may be used, subject to

approval by the USPTO, if they are not likely to be

confused with existing conventional symbols, and if

they are readily identifiable. 

Legends

Suitable descriptive legends may be used, or may be

required by the examiner, where necessary for

understanding of the drawing, subject to approval

by the USPTO. They should contain as few words

as possible. 

Numbers, Letters, and

Reference Characters 

The English alphabet must be used for letters, except

where another alphabet is customarily used, such as

the Greek alphabet to indicate angles, wavelengths,

and mathematical formulas. 

Reference characters (numerals are preferred), sheet

numbers, and view numbers must be plain and

legible, and must not be used in association with

brackets or inverted commas, or enclosed within

outlines (encircled). They must be oriented in the

same direction as the view so as to avoid having to

rotate the sheet. Reference characters should be

arranged to follow the profile of the object depicted. 

Numbers, letters, and reference characters must

measure at least 0.32 cm. (1/8 inch) in height. They

should not be placed in the drawing so as to interfere

with its comprehension. Therefore, they should not

cross or mingle with the lines. They should not be

placed upon hatched or shaded surfaces. When

necessary, such as indicating a surface or cross

section, a reference character may be underlined and

a blank space may be left in the hatching or shading

where the character occurs so that it appears distinct.

11
A Guide to Filing a Utility Patent Application

United States Patent and Trademark Office

12

The same part of an invention appearing in more than

one view of the drawing must always be designated

by the same reference character, and the same

reference character must never be used to designate

different parts. 

Reference characters not mentioned in the

description shall not appear in the drawings.

Reference characters mentioned in the description

must appear in the drawings. 

Lead Lines and Arrows

Lead lines are those lines between the reference

characters and the details to which they refer. Such

lines may be straight or curved and should be as short

as possible. They must originate in the immediate

proximity of the reference character and extend to

the feature indicated. Lead lines must not cross each

other. Lead lines are required for each reference

character except for those which indicate the surface

or cross section on which they are placed. Such a

reference character must be underlined to make it

clear that a lead line has not been left out by mistake.

Lead lines must be executed in the same way as lines

in the drawing. 

Arrows may be used at the ends of lines, provided

that their meaning is clear, as follows: 

■ on a lead line, a freestanding arrow to indicate

the entire section toward which it points; 

■ on a lead line, an arrow touching a line to

indicate the surface shown by the line looking

along the direction of the arrow; or 

■ to show the direction of movement. 

Copyright or Mask Work Notice 

A copyright or mask work notice may appear in the

drawing, but must be placed within the sight of the

drawing immediately below the figure representing

the copyright or mask work material and be limited

to letters having a print size of 0.32 cm. to 0.64 cm.

(1/8 to 1/4 inches) high. The content of the notice

must be limited to only those elements provided for

by law. For example, "©1983 John Doe" (17 U.S.C.

401) and "*M* John Doe" (17 U.S.C. 909) would be

properly limited and, under current statutes, legally

sufficient notices of copyright and mask work,

respectively. Inclusion of a copyright or mask work

notice will be permitted only if the authorization

language set forth in 37 CFR §1.71(e) is included at

the beginning (preferably as the first paragraph) of

the specification. 

Numbering of Sheets of

Drawings and Views

The sheets of drawings should be numbered in

consecutive Arabic numerals, starting with 1, within

the sight (the usable surface). These numbers, if

present, must be placed in the middle of the top of the

sheet, but not in the margin. The numbers can be

placed on the right-hand side if the drawing extends

too close to the middle of the top edge of the usable

surface. The drawing sheet numbering must be clear

and larger than the numbers used as reference

characters to avoid confusion. The number of each

sheet should be shown by two Arabic numerals placed

on either side of an oblique line, with the first being

the sheet number and the second being the total

number of sheets of drawings, with no other marking. 

The different views must be numbered in

consecutive Arabic numerals, starting with 1,

independent of the numbering of the sheets and, if

possible, in the order in which they appear on the

drawing sheet(s). Partial views intended to form one

complete view, on one or several sheets, must be

identified by the same number followed by a capital

letter. View numbers must be preceded by the

abbreviation FIG. Where only a single view is used

in an application to illustrate the claimed invention, it

must not be numbered and the abbreviation FIG.

must not appear. 

Numbers and letters identifying the views must be

simple and clear and must not be used in association

with brackets, circles, or inverted commas. The view

numbers must be larger than the numbers used for

reference characters. 
United States Patent and Trademark Office

A Guide to Filing a Utility Patent Application

Security Markings

Authorized security markings may be placed on the

drawings provided they are outside the sight,

preferably centered in the top margin. 

Corrections

Any corrections on drawings submitted to the

USPTO must be durable and permanent. 

Holes

No holes should be made by the applicant in the

drawing sheets. Rather than use of a staple, a nonhole producing binder clip should be used.

13

Patent and Trademark Depository Library (PTDL) Program

The Patent and Trademark Depository Library Program is comprised of a network of Patent and

Trademark Depository Libraries (PTDLs) located in the 50 states, the District of Columbia, and Puerto

Rico which provide access to many of the same products and services offered at the USPTO search

facilities in Arlington, VA. The scope of PTDL collections, hours of operation, services, and fees (where

applicable) vary depending on PTDL location. Users are advised to call ahead to determine products and

services available at a particular PTDL. PTDLs also offer automated access to patent and trademark

information. All PTDLs offer free access to the Cassis CD-ROM series search tools to assist patrons in the use

of patent and trademark collections. Please refer to the USPTO’s Web site for a complete list of PTDLs.
A Guide to Filing a

Utility Patent Application