Claim of priority to an earlier filed patent application

What is a claim of priority?

A claim of priority is a reference in a later filed patent application back to an earlier filed patent application.

What is the benefit?

The claim of priority allows the later-filed application to enjoy a priority date as of the filing date of the earlier filed patent application and not the actual filing date of the later filed patent application.  If the later filed patent application is rejected based on intervening prior art dated between the two filing dates of the earlier and later-filed patent applications, the claim of priority eliminates that intervening reference as prior art.  That can be the difference between an allowance or rejection of a patent application.

Does everything in the later filed patent application enjoy a priority date over the earlier filed patent application?

The claim of priority does not give the later filed patent application the benefit of the filing date of the earlier filed patent application for everything described or disclosed in the later filed patent application.  Rather, only those things that are described in both the earlier and later-filed patent applications enjoy a priority date of the earlier filed patent application.

A good way to understand this concept is to cover the terms used to describe the various types of patent applications.  A continuation patent application is a refiling of the original patent specification of the earlier filed patent application with claims relating to the same invention.  A divisional patent application (MPEP 201.06) is a refiling of the original specification of the earlier filed patent application with claims relating to a different aspect of the invention.  A continuation in part application is a refiling of the original patent specification and includes new features of the invention and has claims directed to the new features.

A claim of priority in a continuation or divisional patent application enjoys the priority date of the earlier filed patent application because they share the same specification.  Everything described in the later-filed application is also described in the earlier filed patent application.  For a continuation in part application, the later filed patent application enjoys the earlier priority date only for the common subject matter and not for the new features.  The new features have an effective filing date as of the filing date of the continuation in part application.

Using a claim of priority to develop a patent portfolio around cornerstone technology

A claim of priority is made in a later filed patent application back to an earlier filed patent application when developing a portfolio of patents around cornerstone technology or technology that is important to a business.

A patent portfolio is a group of patents that may or may not be related to each other by a claim of priority.  For those that are related to each other by a claim of priority, they share a common specification.  The later filed patent application is a refiling of the earlier filed patent application with a new set of claims and includes the claim of priority.

Because of the claim of priority, the earlier filed patent application is not prior art to the later filed patent application at least for the common subject matter between the two. Otherwise, the earlier filed patent application when it matures into a patent or is published as a pre-grant publication will be prior art against the later filed patent applications which will be devastating to the later filed patent application because it is almost impossible to overcome your own patent application if it becomes prior art.

How do you make a claim of priority?

The requirement for making a claim of priority is discussed in Manual of Patent Examining Procedure (MPEP) Section 211: Claiming the Benefit of an Earlier Filing Date Under 35 U.S.C. 120 and 119(e).  For information on claiming priority to a foreign patent application, see MPEP Section 213: Right of Priority of Foreign Application.

A claim of priority in a later filed patent application can be made to an earlier filed provisional patent application, nonprovisional patent application, a design patent application, or a foreign patent application.

The following highlights the more crucial aspects of the claim of priority.

A claim of priority is made when:

1. The later filed patent application includes a specific reference to the earlier filed patent application;
2. The specific reference is made within 16 months from the filing date of the earliest priority application or 4 months from the filing of the later filed patent application;
3. The later filed patent application is filed before the abandonment or grant of the earlier filed patent application. The earlier and later filed patent applications must be co-pending with each other at some point in time.

Specific reference

The specific reference is a statement in the later filed patent application which refers back to the earlier filed patent application.   The specific reference must specify:

1. Application Serial Number of the earlier filed patent application and
2. The relationship (e.g., continuation, divisional, continuation in part, provisional) between the earlier and later filed patent applications.

The specific reference is made by inserting the information in the Application Data Sheet (ADS).  The ADS is a document submitted with the patent specification.  The patent specification along with the ADS form a part of the overall patent application package.  The section of the ADS that needs to be filled out is shown in the example below.

Timing of specific reference

The specific reference needs to be made during a certain period of time.  It needs to be made within 16 months of the filing of the earliest filed patent application or 4 months after the filing of the later filed patent application.

Co-pendency requirement

The later filed patent application needs to be filed with the United States Patent and Trademark Office before the earlier filed patent application is abandoned or granted.   For example, if a provisional patent application is filed, the nonprovisional patent application must be filed while it is pending.  The provisional patent application is pending only for one year from its filing date.  When a nonprovisional patent application is allowed, then the follow-on patent application needs to be filed before it is granted.  If a patent application is rejected, then the follow-on patent application needs to be filed before the due date to file a response (i.e., date of abandonment).

How do you fix a defective claim of priority?

You can identify a defective claim of priority by checking the filing receipt, a picture of which is shown below.  The red box identifies the section of the filing receipt that identifies the domestic and foreign claim of priority.

A defective claim of priority may be fixed before the patent application is granted through a petition to the Patent Office or after the patent is granted by way of a reexamination request.  The cheaper method is the petition.  The reexamination proceeding is a significantly more expensive procedure.  For both methods, the reason for the defective claim of priority must be unintentional.  A claim of priority can be fixed with a certificate of correction if the mistake was made by the Patent Office.

Reference MPEP 201 for the various petitions for fixing a defective claim of priority.

I invite you to contact me with your patent questions at (949) 433-0900. Please feel free to forward this article to your friends. As an Orange County Patent Attorney, I serve Orange County, Irvine, Los Angeles, San Diego, and surrounding cities.