Continuation applications are wonderful tools for increasing the size and scope of your patent portfolio. With some careful planning, you can use continuation applications to turn your experience with the patent office and your knowledge of the prior art into multiple patents that provide broader or interlocking patent protection. In some cases, you can also use continuation applications to prevent competitors from introducing new products, even after your original patent application has issued as a patent. And you can use continuation applications to synchronize your patent procurement with your funding and corporate strategy without sacrificing your patent rights.

What is a continuation application?

A continuation application is a patent application spawned from an earlier patent application, called a parent application. A continuation application has the same description, drawings, and priority date as the parent application, but different claims. Often, the claims in a continuation application are broader than the claims in the parent application or cover a different aspect of the technology described in the parent application. For example, you can file claims in a continuation application based on how the patent office examined the parent application. You can also use the claims in a continuation application to cover products or services that appear in the market after the parent application has issued as a patent.

Why should I file a continuation application?

You should file a continuation application because you can use it to write new claims that get an early original priority date. The priority date is the effective filing date of the patent application The patent office uses the priority date to determine which references count as “prior art” for rejecting your claims. Generally, earlier priority dates are better than later priority dates because less prior art is available. At the same time, however, by the time you file the continuation application, you may know more about the market, your technology, and your competitors’ technology. This allows you to write new claims that cover technology that is valuable today. And because these new claims have the priority date of the original patent application, they are not subject to challenge based on more recent art.

For example, consider what could happen if one of your competitors introduces a new product that is described in one of your patents. If the claims in your patent don’t cover the new product, you can pursue a continuation application with claims that are based on the description in the original patent and that cover the new product. The patent office will give the continuation application a priority date corresponding to the filing date of the original patent application, so the new product may not be prior art to the continuation application, even if you file the continuation application after the new product is introduced.

When can I file a continuation application?

You can file a continuation application so long as at least one patent application in the family is pending. If you would like, you can file successive generations of continuation applications (e.g., children, grandchildren, etc.) for up to about 20 years after the priority date of the parent patent application.

You can file continuation applications in sequence, in parallel, or both—as long as there’s one case alive in the family, the timing is up to you. This creates great flexibility both in terms of expanding a patent portfolio quickly (e.g., in response to a competitor’s activities) and in terms of incurring cost (e.g., defer costs until funding is available). In addition, the incremental cost of preparing and filing a continuation application is relatively small, which leverages your investment in the parent application.

How can I use a continuing application strategically?

Continuation applications can be used to expand a patent portfolio relatively quickly and inexpensively. They can also be used to create interlocking patent protection that covers a market or technology more completely and is less susceptible to invalidation in litigation. In addition, the timing for filing continuation applications is very flexible, so you can file them based on new technology developments, evolution of the market, and your budget.

One strategy that often works well for start-ups is to file a first patent application with claims that cover the initial product and are of relatively modest scope. Because the claims are modest in scope, they may be allowed relatively quickly, all other things being equal. And because the claims are directed to the initial product, they should also push the patent examiner to identify the prior art that is closest to the initial product. You can use the patent examiner’s examination of these claims and the identified prior art to write potentially broader claims for the continuation application that should also be allowed relatively quickly, assuming the patent examiner does not find any other relevant prior art.

Divisional Applications and Continuations-in-Part (CIPs)

In addition to continuation applications, the USPTO also permits two similar types of patent applications:

A divisional application also has the same description, drawings, and priority date as the parent application (just like a continuation application), but includes claims that were filed with—and restricted from—the parent application. Basically, if the patent office decides that the parent application includes claims to different inventions, you will have to pick claims to one invention for the parent application and file the claims to the other invention(s) in a divisional application. A continuation-in-part (CIP) has new description and drawings in addition the description and drawings from the parent application. Any claims in the CIP based solely on the description and drawings from the parent application will get the priority date of the parent application. And any claims based on the new material or a combination of the new and old material will not get the priority date of the parent application.

Continuation applications, divisional applications, and CIPs offer many advantages, but can come with disadvantages as well. Using them effectively involves careful planning.