Can you add new content after filing a patent application?
Yes, it is possible to add new content after filing a utility patent application. However, there is a catch. The new matter is not added in the way you might think. Procedurally, the new subject matter is added not to the first patent application that has already been filed, but rather to a second application that will be linked to the first. That subsequent application is called a continuation-in-part application, or a CIP application. So, you would end up with two patent applications: a parent application and a child CIP application..
What is a CIP application?
A CIP application is one type of a continuing application, or child application, that stems from a parent application. What makes a CIP application different from other types of continuing applications is the addition of new subject matter that is not sufficiently disclosed in the parent application.
What constitutes new matter?
To answer this question, we start with the claims. On a claim by claim basis, does the specification of the parent application adequately support and enable all the features of a particular claim? If not, then disclosures added to a specification will most likely be considered new matter.
New drawings (i.e., new figures as opposed to formal drawings of existing figures) are almost always considered new subject matter. When it comes to the written description, there may be some flexibility to add some textual language that would not be considered new matter. For example, clarifying a feature that is already illustrated in an existing drawing might not be new matter. Clarifications of other previously disclosed features might possibly be allowed in the parent application.
For example, suppose you filed a patent application that disclosed a fairly straightforward mechanical structure, such as a tube. You assumed that it was common sense that a tube had to be hollow, so you never explicitly used the term “hollow” to refer to the absence of material in a tube. You are then confronted with an Office Action where prior art is being applied that shows solid structures which the examiner is interpreting as tubes.
So you now want to go back to your description and add negative descriptions (i.e., what the structure is not) so that you can claim negative limitations. In such circumstances, it may worthwhile to consider a straight continuation application which may add some clarifying language to the detailed description without adding new subject matter. This is a tricky issue that would warrant discussion with your patent practitioner.
When do you need to make a decision on a CIP application?
It’s not an uncommon desire to add new matter to an already-filed patent application. Sometimes inventors think of new features after a utility patent application has already been filed. It’s also possible that broad concepts generally described in the original patent application need to be fleshed out in greater detail and supplemented with more specific examples.
Will the CIP application have different priority dates?
Yes, a CIP will have different priority dates for the original content and the new matter. A CIP application will maintain the earlier filing date of the patent filing (“priority date”) for all the subject matter disclosed in the earlier filing, and will receive a later priority date for the new matter added to the CIP.
For example, suppose a first utility nonprovisional patent application disclosing features A and B is filed on January 1. While this “parent” application is still pending, a CIP is filed on March 1 that same year disclosing features A, B and C. Accordingly, features A and B in the CIP will maintain the earlier Jan. 1st priority date while feature C will be accorded a March 1st date.
How to add new content to a provisional patent application (PPA)
If the original application was a provisional patent application, new descriptions may be added in the non-provisional filed within 12 months of the provisional, but the same principle applies. Any new matter introduced in non-provisional application that is not supported by the provisional application will not get the benefit of the earlier provisional filing date. A provisional application, therefore, is only as valuable as whatever content is included in the filing.
You could also include additional details in a series of subsequent provisional applications filed within 12 months of the first provisional, and then consolidate all the details into a single non-provisional application filed within 1 year of the first provisional application. This would result in staggering priority dates for the new features introduced in each provisional.