The termsfiling dateandpriority dateare often used interchangeably, but they are not the same. Thefiling dateis the date when a patent application is first filed at a patent office. Thepriority date, sometimes called the “effective filing date”, is the date used to establish the novelty and/or obviousness of a particular invention relative to other art.
Thepriority datemay be earlier than the actualfiling dateof an application. If an application claims priority to an earlier parent application, then itspriority datemay be the same as the parent.
There are a number of situations where a patent application may claim priority to an earlier application. These include:
- Continuation applications (including continuations, divisionals, and CIPs).
A patent application may claim priority to an earlier filed parent application. When this occurs, thepriority dateof the new application is usually the same as thepriority dateof the parent application. - Domestic applications based on foreign or international filings.
If a patent application is first filed in a foreign country, or as an international (PCT) application, and then filed domestically (usually within a year the foreign or international filing), then the application that is filed domestically may claim thefiling dateof the application in the foreign country as itspriority date. - Patent filings based on US provisional patent applications.
In the US, an applicant may file a provisional patent application, and then file a full-length application within one year. In this case, thepriority datefor the full-length application is the date of the provisional application filing.
In many cases, a patent application claims priority to a series of applications. For example, a continuation application may claim priority to a parent utility application, which claims priority to a US provisional application. The new application may then claim priority to the first filed application in the series, which in this case, is the provisional application.
If a patent application is an original, non-provisional patent application, not a continuation application, and not previously filed in another country, itsfiling dateis usually the same as itspriority date.
