Legal Definitions - grandparent application

A grandparent application is a type of patent application that is the first-filed application in a chain of at least three continuation or continuation-in-part patent applications. It is called a grandparent application because it is the oldest or first in the family of related applications.

For example, if an inventor files a patent application and then files two more related applications that build on the original application, the first or oldest application is the grandparent application.

The grandparent application is important because it establishes the priority date for the family of related applications. This means that any new invention or improvement that is added to the family of applications will have the same priority date as the grandparent application.

Overall, a grandparent application is a key part of the patent application process and helps inventors protect their intellectual property.