After deciding to file for a patent, some entrepreneurs want to include all their ideas in one application, while others want to file every variation of their invention in a separate patent application. What are the pros and cons of these two approaches?

Filing one patent application with all variations of an idea

When you have material that you want to patent, it may appear to you to be a disparate mixture of intellectual property (IP) that is not clearly going to fit as one invention. The question arises whether to initially file it as one patent with a large amount of information, or to break it up into what seems like logical chunks.

It is usually best to err on the side of putting too much in one patent application. This is because if you split it up into more than one patent application, there is a risk that the patent will be deemed invalid due to the “double patenting” doctrine.

Rather than take a chance on being cited for double patenting, cite all of the description and claims in a single patent application.

During the patent examination process, the patent office may hold that your claims define different inventions and that you need to restrict the application to one of several inventions listed. At that point, you can file a divisional application for the other claims.

You do not lose the priority date of filing because the divisional application receives the same priority date as the parent application. Case law indicates that you are not at risk for double patenting when an examiner has required the division of claims.

This presents a win-win situation because if an objection by the patent office is not made, the applicant may have all the claims issued in one patent and save money on fees.

If restriction is required, a double-patenting objection can be answered on the basis that the applicant was forced to file a divisional application (and the parent and the divisional both keep the original priority date).

A cautionary note in filing a single patent application

A disadvantage of putting all your information in a single application may arise if that information is later used against you as prior art.

Keep in mind that your patent application will be published at 18 months, so the details therein potentially serve as prior art against you if you file a future patent application. Therefore, be prudent in what you include in your patent application.

Note: The content in this article is for purposes of general information only. It is not legal advice.