What Are the Different Types of Patent Applications?

Patent applications fall into three broad categories: utility, design, and plant applications. Design applications protect only the ornamental appearance of a product, not its functional features. Thus, they are of interest primarily to companies concerned about the appearance of their products, particularly where that appearance promotes sales or otherwise affects value.

Plant applications are, by far, the fewest filed. They protect certain new plant varieties under relatively specialized circumstances.

Utility applications protect how an invention works—its structure, function, and use. It is these applications that most inventors and companies are concerned with when they think about patenting their inventions. There are three primary types of utility applications that an inventor typically uses: provisional applications, U.S. national applications, and PCT (international) applications.

A provisional application is often used as the initial starting point for an invention. It allows a company to establish an early filing date and may be strung together over a period of a year to accommodate changes that would be more difficult and more expensive using other filing options. Provisional applications are also not published. Thus, if an applicant abandons a provisional application, there need not be public disclosure of the invention, and, if done properly, the inventors may modify their invention and file again at a later time without necessarily disclosing the earlier version. Although provisional applications automatically expire one year from the date on which they are filed and are not examined, they can provide priority for inventions subsequently claimed in a U.S. national application or a PCT application.

Unlike provisional applications, U.S. national applications undergo prosecution and may issue as a patent. There are also mechanisms available for accelerating prosecution. Accordingly, if obtaining an issued patent quickly is a primary objective, a U.S. national application is generally the better choice.

When protection outside the United States is desired, a PCT application is usually the most practical option. Although a PCT application will never itself issue as a patent, it allows a single application to enter the national stage in multiple jurisdictions, thereby simplifying what would otherwise be a country-by-country filing process. A PCT application can be filed together with a U.S. national application or, alternatively, a single PCT application can be filed and later enter the U.S. national stage.

These different types of applications are often used together. For example, an inventor might begin with a provisional application, follow it with a U.S. national application, and at the same time (or shortly thereafter) file a PCT application to preserve international rights. A PCT application, in turn, may later enter the U.S. national stage, at which point it is examined in essentially the same way as any other U.S. non-provisional application.

Seen from this perspective, a useful way to understand the system is that, regardless of how the process begins, every U.S. utility patent must ultimately pass through the same examination channel. The filing of a U.S. national application or a U.S. national stage application does not create a different end point—they simply provide different routes to reach the same examination framework.

As the patent process continues, additional types of applications can come into play, particularly where it becomes necessary to refine or adjust the scope of protection based on earlier filings. These are important tools, but they arise only after the initial filing has occurred and are best considered in a separate context.

The essential point to remember is that choosing a type of patent application is not merely a procedural choice. It is part of a broader strategy. The appropriate approach depends on how fully the invention has been developed, how quickly a filing must be made, whether international protection is being considered, and how resources are allocated over time. Understanding the different types of patent applications provides the foundation for making those decisions in a deliberate and informed way.

Disclaimer: This piece is provided for general informational purposes only and does not constitute legal advice. Patent issues are often complex and highly fact-specific, and no one should act on general information of this kind without consulting qualified patent counsel regarding the particular circumstances involved.