Do I Need to File a Divisional Patent Application? Episode 57

Continuing Patent Applications Overview

In the last episode, I gave a broad overview of the different types of continuing patent applications. If you haven’t listened to that episode yet, I recommend going back and doing so. In this episode, I’ll be focusing on one specific type of continuing patent application—the divisional application. This is probably the most straightforward type of continuing application in terms of when you should file one.

What Is a Divisional Application?

I briefly discussed divisionals in the episode about restriction requirements. If you recall, a restriction requirement occurs when the examiner determines that your application contains claims for two different inventions. You are then required to choose one invention for examination and to withdraw the claims related to the second invention.

Let’s say your first invention is allowed. What happens to the second invention that was never examined? That’s where a divisional patent application comes in. A divisional application is essentially a new application that is identical to your first application, except that you remove the allowed claims and include only the claims that were withdrawn due to the restriction requirement.

How to File a Divisional Application

When you file a divisional application, the examiner will then examine the claims that were withdrawn from your original application. The new application claims priority to your original application.

In one of the first lines of the new divisional application, you must include a section titled “Cross-Reference to Related Applications.” When you first file a patent application, you either omit this section or simply state "None." However, in a divisional application, you must write something like:

"This application claims priority to and is a divisional application of U.S. Application No. [application number], filed on [filing date]."

That’s all that is required. You must state that you are claiming priority, specify that it is a divisional application, provide the original application number, and include the filing date of the original application.

Why Is Priority Important?

If you correctly claim priority to your first application, the examiner is not allowed to consider any prior art that was introduced after the filing date of your first application. This means that any developments, competing products, or newly published materials that appeared after your original filing date cannot be used against your divisional application.

Examination and Patent Term

Once the divisional application is filed, the examiner will review it just like any other application. You may receive rejections, objections, or requests for amendments. If the divisional application is allowed, it will be issued as its own separate patent, with its own patent number.

However, it is crucial to understand that the 20-year patent term is measured from the filing date of your first application—not from the filing date of your divisional application. This means you do not get an additional 20 years from the date of filing your divisional application; rather, your patent term is counted from your original application’s filing date.

When Should You File a Divisional Application?

The decision to file a divisional application is simple. If you were required to withdraw claims from your first application because they were deemed to cover a second invention, and you still want patent protection for that second invention, then you should file a divisional application.

However, if you are no longer interested in obtaining a patent for that second invention, you may choose not to file a divisional application.

Timing Considerations

One of the most important things to remember is that a divisional application must be filed while your original application is still pending. You cannot wait until after your first application has been granted to file a divisional.

If you receive a Notice of Allowance for your first application, make a note of the grant date. You must file your divisional application before your first application issues as a patent. If you miss this deadline, you lose the ability to file a divisional application for the withdrawn claims.

Final Thoughts

That covers the basics of divisional patent applications and when you should consider filing one. I’m Adam Diament, and until next time—keep on inventing!