A patent application is an official document filed in the United States Patent and Trademark Office (USPTO) that stakes a claim for legal protection to an invention. To write a patent application is not a simple task. It takes time, patience, and understanding of a very complex legal process fraught with formalities and proper formatting requirements. Writing a patent application well enough to get a patent issued is widely considered an art form. 

This article is about how to write a patent application generally. It includes a discussion of the content necessary for each of the ten essential sections that must be addressed in order to write a patent application. In addition to the written sections of a patent application there are several USPTO forms required. There are additional requirements for patent applications filed under the USPTO’s Accelerated Examination Program for utility patent applications to get allowance and issue or rejection within 12 months. Read more about accelerated examination patent applications.

Patent Attorney Writing the Patent Application
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Important Tip: Patent applications have a lot of required parts to ensure claims are fully enabled and determinable. Well written patent applications offer broad and comprehensive protection of invention if allowed and issued. Each section of a patent application is very important when it comes to issuance. It is recommended you work with a patent practitioner when writing a patent application. Read more about why you might want to use a licensed patent writer. Note: Each country has different guidelines for patent applications. This article concerns specifically the writing of a U.S. utility patent application. 

Writing the Required Parts of a Patent Application

For how to write a patent application, there are as many as 45 sections required for a complete and proper utility patent application depending on the invention and circumstances of the patent application filing. Importantly, there are 10 essential sections that you must address to file a complete patent application. While we do not have a how to write a patent application pdf, there are 2 USPTO .docx templates available from their website: one for the 10 essential sections and a second one that includes all 45 sections.

The vast majority of the time, to write a patent application for a utility patent the application will rely on the 10 essential sections. These 10 sections, plus an oath that the inventor invented the claims, and the filing fee are all that is required for a complete and proper patent application if written well and properly.

Important Tip: U.S. patent applications must be in English. If not, a translation is required. 

The 10 Essential Written Sections of a Patent Application

This how to write a patent application includes information on writing the 10 essential sections to a good patent application that is complete and proper. Even though some sections are only needed if applicable, it is important that the sections are in the correct order. The order of the sections is one of the procedures from the USPTO on how to write a patent application. The details and some tips and tricks on how to write a patent application are discussed for each of the 10 sections in order. The ten essential sections to write a patent application include the: 

  1. Title of the Application
  2. Cross-Reference to Related Applications
  3. Background of the Invention – Technical Field;
  4. Background of the Invention – Background Art
  5. Summary of the Invention
  6. Brief Description of the Drawings
  7. Detailed Description of the Invention
  8. Claims
  9. Abstract; and
  10. Drawings.
Patent Attorney Writing the Patent Application

Title of Application

The title of an application is first and is the heading on the first page of the specification of a patent application. The title briefly describes the invention in the patent application. If the invention at hand can perform a variety of uses, it is best to find a common denominator for each use and summarize as the title of your patent application. To best write a patent application title, use language that is Plain and simple. 

If it occurs that the title does not appropriately describe the invention, the patent examiner may request a title change. The patent examiner will also likely request a title change if the title contains words such as “a,” “an,” “the,” and even words like “new” or “improved,” as these words should not be used in a patent application title. The title should be simple and to the point. It should not exceed more than 500 characters in length. When it comes to choosing a title for a patent application, something short, descriptive, and accurate is the way to go.

The second section of a patent application is cross-referencing to related applications. Cross-referencing refers to the inclusion of identifying information for any related patent applications in a section titled “Cross-Reference to Related Applications.” 

For example, if a provisional patent application (PPA) was filed for the same invention previously, cross-referencing is especially important in order to benefit from the early filing date of the PPA. The proper format for cross-referencing a previously filed provisional patent application: “This application claims benefit under 35 U.S.C. § 119 to provisional patent application number ##/###,###, filed on month day, year.”

Many times there are no related patent applications. If that is the case, you can delete this essential section. It is essential because if there are related applications, they must be disclosed. Another common example is when you receive an office action that requires new matter to overcome, so you file a continuation-in-part application. The proper format for cross-referencing a previously filed non-provisional patent application that you are adding new matter to “This application claims benefit to the earlier filing date and right of priority under 35 U.S.C. § 120 to patent application number ##/###,###, the contents of which are herein incorporated by reference under 37 CFR 1.57(b).”

Background of the Invention

The third and fourth essential sections are included in the Background section which is comprised of two subsections. Essential sections 3 and 4 to write a patent application that is compete and proper are the two subsections that are the Background of the Invention. These two essential sections in how to write a patent application that is compete and proper are titled the “Technical Field” and the “Background Art.” 

Technical Field

The first subsection of the Background is the Technical Field section. This section is a statement about what field/art the invention applies to. This typically points out the issue that the invention aims to solve. You can paraphrase the technical field information from any applicable U.S. patent classification definitions of the subject matter. Look at this section in any of the applicable prior art patents and patent applications to help get the idea of how this section is worded for patent applications in the same field as the invention being described in the patent application. 

Background Art

The second subsection of the background is the Prior Art, or Background Art. This section is where prior art is discussed. It is a good idea to specify prior solutions and patents that had shortcomings or failed to create the solution for the issue at hand. Background art, or prior art, is also listed on a form called the Information Disclosure Statement, or IDS. Read about how to do a patent search.

Patent Filing Tip for how to write a patent application: Fill out and submit the IDS with the initial filing of the patent application. You can always amend it later, and it is a required submittal. 

Summary of the Invention

The fifth section in how to write a patent application that is complete and proper is the Summary of the Invention section. This is the first portion of the patent application that discusses the elements and/or features of the invention. The nature and basic idea of the invention should be disclosed. This section should contain a complete, but brief, summary of the invention details. Be sure to include the details and structure of the claims. An inventor’s reasoning and inspiration behind the invention may be also discussed in this section of the patent application.

Brief Description of the Drawings

The sixth essential section in how to write a patent application that is complete and proper is the Brief Description of the Drawings. Like the cross-reference to other applications section earlier, this section can also be deleted if there are no drawings, figures, flowcharts, or diagrams needed. Technically, drawings are only required if the patent application requires visuals to describe how to make and use the invention. This is what the patent office refers to when they say the invention admits of illustration. 

If an invention admits of illustration (the application needs drawings, figures, flowcharts, or diagrams), this section is essential. When briefly describing a drawing of an invention, applicants should name each different drawing or figure with a letter or number. This allows for clarity when referencing different elements or parts of the drawings or figures as they are identified in the Detailed Description below. 

Detailed Description

The seventh section in how to write a patent application that is complete and proper is the Detailed Description. This section lays out all of the details of the invention. The patent examiner should be able to conclude that someone of ordinary skill in the art would be able to make and use the invention if they were to read the patent application. This is called the enablement requirement. The Detailed Description must meet the enablement requirement. 

Enablement Requirement

For how to write a patent application, the enablement requirement guarantees that the patent application’s specifications are clear and comprehensively describe how to make and use the invention. This purpose of this requirement is so that once the patent expires, the general public has sufficient information on how to make and use the invention without help from the inventor(s). To meet this requirement, the patent application must describe every aspect of the invention and how all the aspects perform together. 

The detailed description will also have a list of all of the elements identified in the drawings. It is important to label and discuss each element that is claimed. The detailed description must fully enable all elements of all claims. There must be sufficient detail that the invention can actually be made and used as intended. In addition to the many other potential objections and rejections, a full disclosure of the invention must be provided or there will not be a notice of allowance and issue of a patent. It is important to include the various embodiments of the invention. 

Embodiments of the Invention

For how to write a patent application, a patent embodiment is the overall description of the invention claimed in a patent application. This description is comprised of the production, use, practice, or expression of an invention. Different embodiments of an invention refer to another model of the invention. It is important to describe as many different embodiments as practical or possible, regardless of whether the applicant will put all embodiments to use and into production. 

Embodiments consider all the different ways an invention could be made or put to use. This is to ensure the patent’s protection is well described and to prevent others from creating something similar to the invention at hand. If one does not describe an embodiment, the embodiment is not a part of the invention. An easy way to think about it is to imagine an invention composed of A + B + C + D. If someone has an almost identical invention but it is composed of only A + B + D, it is not an infringement. To prevent this, one must endeavor to describe all possible versions of an invention. These other versions do not need to be specific. 


The eighth section in how to write a patent application that is complete and proper, is the most important section – the claims. The claims of a patent application define the legal boundaries of protection contained in a patent. Each claim identifies an innovative feature of an invention and its elements in context. The claims section is the differentiating factor of a patent application and are examined against the four criteria for patentability. It is recommended one begins writing a patent application by drafting the claims of the invention first. The claims section creates a foundation for the rest of the application. 

Claims are tedious to write due to the particular guidelines laid down by the USPTO, guidelines such as the fact that there must be no other material on the same page as the claims of an invention. Each claim must be numbered in Arabic numerals. Claims need to be written in a way that each claim is only one sentence supported by clear language regardless of the length. This must be achieved without the use of lengthy technical language. 

Claims should be complete, precise, and have adequate support in terms of what realm they intend to cover. They need to be current and have an applicable scope, whether that is broad or specific. When writing claims, it is important to consider the scope, characteristics, and structure.

Important Note: Utility patents are allowed the inclusion of 20 claims total in the basic fee – 3 independent claims and 17 dependent claims. There is no limit on the number of claims, but more than 20 requires additional fees. 

Claims should contain two declarations: one that is broad and general and one that is specific. Broad general declaration describes broad terms of invention without pointless ideas. The broadest claim should be the first claim. Specific declaration considers all realistic possibilities.

There is a structure that must be followed when writing claims. This structure includes an introduction phase, followed by body, and finishes with an interlink between the introduction phase and body. The introduction phase is meant to introduce the invention at hand and describe its purpose. The body portion should contain the legal description that entails the exact ideas the applicant is wanting protection for. The interlink portion connects the two previous portions and reveals how restrictive or permissive the patent application is.

Abstract of the Invention

The ninth essential section in how to write a patent application that is complete and proper is the abstract. After the claims, an abstract is required. An abstract is a brief summary of the invention that needs to be less than 150 words. The abstract should completely summarize the invention and its uses. 

Abstracts are frequently used by people performing prior art searches to be able to quickly assess whether a patent application has relevance to an invention they are seeking to patent. 

Abstracts can be found on the front page of a patent or patent application once it is published. However, when it comes to how to tie a patent application, it is typically the last page of the written patent application specification, unless there are drawings are added to the document.  

Drawings or Figures may be needed for a Patent Application

The tenth, and final, essential section to write a patent application that is complete and proper is the drawings, if needed. Like the Cross-Reference and Brief Description of the Drawings sections above, the drawings are only essential if the invention admits of illustration (needs drawings to be clearly understood). To write a patent application you are not required to provide drawings, but, drawings are nearly always necessary.

To write a patent application that includes figures or drawings there are format, numbering, and size requirements. There are many guidelines patent drawings are required to follow issued by the USPTO. Drawings should be created so that they show relationships between claimed elements and piece together any missing information needed to understand the invention at hand. They should be created with black ink on white paper. Every patent application does not require a patent drawing, but it is advised to include them to simplify writing the Detailed Description above. 

If the patent application is filed online, the drawings must be in electronic format as images or *.pdf documents, or included in the template above. When you write a patent application the Patent drawings must be numbered, beginning at 1, in order to be easily referenced.

The Forms, Inventors Oath or Declaration, and Fee Complete a Patent Application

For how to write a patent application, in addition to the 10 essential written sections, there are two forms, the oath or declaration that the inventor invented the subject matter claimed, and the filing fee. The two required forms are the Application Data Sheet (ADS), and the Information Disclosure Statement (IDS). The ADS contains all of the demographic information for the invention. The IDS is the list of prior art that was considered in writing the patent application.

There is a requirement for the inventor to swear an oath or make a declaration that they believe they are the inventor of the subject matter claimed in the patent application. The USPTO requires that every inventor named on a patent application give an oath or declaration. By signing this oath or declaration, the inventor(s) declare that (1) the application was made by or authorized by the declarant (person making the declaration) and (2) the person making the declaration believes himself or herself to be the original inventor of the claimed invention.

Important Tip: When it is time to write a patent application and the original work is written in language other than English, an English translation is also required to complete a patent application.

Conclusion: Writing a patent application is detailed, laborious, and meticulous work. Precision and the use of correct technical language is hard to achieve doing it oneself. The use of ambiguous language in a patent application could create exposure, allowing loopholes for infringement. When considering options for how to write a patent application, be careful. Competent patent writing software does not exist, and patent application forms are not recommended. For this reason, seeking the help of a patent practitioner is always recommended when applying for a patent. Read about invention confidentiality.

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