You may be surprised to learn that the basic requirements of a patent application are fairly simple. A patent application must describe what an invention is, how it is made and how to use it. For a method, the “how it is made” portion should describe how steps of the method are performed. In addition, a patent application should include a declaration by the inventor that the application was made by, or authorized by, the inventor. And, of course, there are fees to be paid to a government patent office.

The inventor’s declaration is a simple form available from the patent office. The patent office will also be happy to tell you what fees to pay and how to pay them. That just leaves the description of the invention and how to make and use it. So, why are patent applications expensive, and why can’t you do it yourself?

The main reason is that, although the basic requirements of the description are relatively straightforward, it takes years of experience to understand how to properly draft a patent application so that it complies with numerous laws and regulations, and so that it broadly protects an invention. Although just about anyone with an appropriate technical background and writing skills could produce a description of the invention (for example, in the form of a typical operating manual), it takes specialized expertise in patent law to produce a quality patent application.

The description typically has several parts. Those parts are the detailed description, one or more claims, and one or more drawings. Drawings are not always required. For example, if the invention is a method or a chemical composition, it may not be necessary to include drawings with the patent application. However, the vast majority of patent applications do include drawings, and it is a best practice to include drawings (even if not absolutely required), since they aid in understanding what the invention is, and how it is made and used.

The detailed description and the drawings typically describe at least one example (also known as an “embodiment”) of the invention. It is a best practice to describe at least two examples of the invention, so it is clear to anyone reading the description that the invention is conceptually broader than any particular details of the described examples. In fact, that principle (the invention itself is more than just the details of the described examples) should be stated in multiple different ways throughout the description, because courts have a tendency to limit a patent’s claims to the details of the described example (and particularly so when only a single example is described as being the invention).

The claims are the most important part of the patent application. The claims define the scope (the “breadth”) of the invention to be protected by a patent. My preferred practice is to draft the claims first, so it is clear in my mind how the detailed description and the drawings should support the claims and their scope, without including unnecessary details of the described examples. Although the claims might be only a small portion of the text of a patent application, in my experience they take a majority of the time to draft the patent application, because they result from a lengthy focused consideration of differences between the inventor’s new concepts and what has previously been done by others. In addition, claims are written in an arcane style (for example, each claim must be written as only a single sentence, even for very complex inventions) and must comply with a variety of complex rules, so it takes a substantial amount of time to perfect the claims.

Some types of patent applications have fewer requirements. A design patent application (known in some countries and regions as an “industrial design” application) does not require a detailed description Drawings included with the application essentially comprise the description, since they illustrate the claimed design. For this reason, design patent applications are typically much less expensive than a normal utility patent application.

A provisional patent application does not require an inventor’s declaration or any claims (although it is a best practice to include at least one claim), and formal requirements are much more lenient for a provisional patent application. However, it is not recommended to skimp on thoroughness of the description in a provisional patent application, since the description must support the claims of an eventual patent, if priority to the provisional application is to be valid. If time and budget constraints allow, a provisional application should be drafted with as much care and attention to detail as a non-provisional application, keeping in mind that the provisional application will be pending for only one year, after which the provisional application’s description must support the claims of the subsequent non-provisional application, in order for the claims to be entitled to the benefit of the provisional application’s filing date.