What Is a Child Patent?

by Shelly Morgan
Unlike their patent counterparts, real parents do not have a priority date.

Unlike their patent counterparts, real parents do not have a priority date.

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When patent attorneys refer to parents and children, they mean something very different than when practitioners of family law use the same words. After you file a patent application, you can file a continuation of that application. The continuation is a new patent application that contains some of the same material as the original application. Under these circumstances, the original application is called the parent and the subsequent application is called a child. Continuations can be filed any time before the parent is accepted or rejected. The Manual of Patent Examination Procedures, commonly known as the MPEP, describes several important types of continuations.

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Discussing patent children and patent parents requires a technical vocabulary. All patent applications include a specification and set of claims. The specification is a narrative, often accompanied by drawings, that describes everything someone skilled in the art needs to know to make and use the invention. Often, it refers to elements that are not part of the invention. The claims appear after the specification. They are written in a very abstract language that specifically sets forth what is novel and non-obvious about the invention. All patent applications have a priority date, which is when the U.S. Patent and Trademark Office, or PTO, received the application.


"Child patent" is an informal name for a continuation patent. Many patent applicants routinely file continuations as a way to augment the claims of the parent. This practice allows the applicant to expand the reach of the parent application and make it a broader, stronger patent. Frequently, in the rush to obtain a priority date, the inventor will not have considered all aspects of the invention that could be claimed. The continuation has the same priority date as the parent. This priority date is very important because it determines when the inventor's legal rights with respect to the invention begin.

Continuation Rules

Applications for continuation patents must be filed with the PTO before the parent patent application issues. Many patent attorneys consult their clients before a patent issues and determine if there is a possibility claims of the parent can be expanded. After the continuation application is filed, the parent application issues.


Several different types of children exist. Divisional patent applications are a type of child in which the original parent application included more than one invention. If this occurs, the PTO will request the applicant describe each invention in a separate application known as a divisional. Divisional applications claim the priority date of the original application.


The continuation-in-part is an exceptional child. Unlike other children, a CIP application can include new matter in both the specification and the claims. CIPs are complicated documents because the new matter might have a new priority date. You should seek the counsel of an online legal service or patent attorney if you contemplate filing a CIP.