Maiorana Patent Law, PA

USPTO - Priority Date

What Is A Priority Date?


In a lot of our blogs, we make reference to whether or not you receive “priority” for the filing. Sometimes we just call this the priority date. This is sometimes referred to as a first filing date. In the official filing receipt, the US Patent Office (USPTO) refers to the original filing date as the 371(c) date. If you only have one application, the filing date is the same date as the priority date. There is also a section called “Domestic Priority data as claimed by applicant” that documents claiming priority to another patent application.

So what does this all mean? In the big picture, when the US Patent Office sends a first Office Action, the Patent Examiner can only use prior art that has been available before your priority date. In a way, the US Patent Office and the Patent Examiner get into a time machine and envision the “state of the art” at the time of your priority date. So if an article, patent publication, or other written publication was available before your priority date, that document can be used as prior art when potentially rejecting your claims. There is a discussion of claim rejections here.

When the Patent Office moved to a first-to-file system (by implementing the AIA), the United States patent system (United States Patent Law) became unforgiving when it comes to delays. This gives an advantage to organizations and individual inventors who are quick to file. It creates a disadvantage for organizations and individual inventors who tend to put things off. This doesn’t mean that someone can steal your invention. What it does mean is that if someone else independently invents something very similar, or the same as your invention, and they file before you do, you will have little recourse in overcoming their patent to be used as a reference against you.

A provisional patent application may, under the right circumstances, establish a priority date. A continuation patent application normally establishes a priority date. A “true” continuation filed that claims priority back to the original filing also gets the benefit of the earlier filing date. Since there are no limits to the number of continuation patent applications that may be filed, an early filing date can certainly be an asset. A continuation-in-part application may or may not establish a priority date. The differences are discussed here.

I thought I was going to keep this super simple, but this sounds complicated again. Bottom line, file as quickly as possible, even if that means filing a provisional application. While budgets are always an issue, they are an issue for everyone. People and organizations who file quickly will have an edge over people or organizations who file slowly. We have seen more than one file that was detrimentally impacted by filing one day later than a competitor. The one day may or may not have been avoidable, but is certainly an issue that should be considered.

So how does an inventor navigate though all the nuances of Patent Law? You don't really need to. We will be your guide to provide quality services at a reasonable price.

Call to set up your initial interview. MI - 586-498-0670 or CA - 408-890-6549.

  • Chris Maiorana
  • August 2017 (updated July 2019)
Topics: United States Patent System, Continuation Patent Application, Priority Date, Patent Law
Related What is RCE?; What is continuation?; What is a patent interference?

If you would like us to analyze your particular situation, call us to set up an appointment to discuss starting an engagement. Please do not send confidential information prior to negotiating an engagement.