The filing date is the date when a patent application is first filed at a patent office. The priority 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.
(4) A provisional application is not entitled to the right of priority under 35 U.S.C. 119, 365(a), or 386(a) or § 1.55, or to the benefit of an earlier filing date under 35 U.S.C. 120, 121, 365(c), or 386(c) or § 1.78 of any other application. No claim for priority under 35 U.S.C.
A priority claim is a helpful, and often critical, way to link a later-filed patent application to an earlier-filed patent application. Known as a priority application, the earlier-filed application must generally have common subject matter and common inventorship in order for a priority claim to be made.
What is a priority date and why does it is matter? A. Priority date refers to the earliest filing date in a family of patent applications. If the earliest-filed patent application for a particular invention was a provisional application, then the filing date of the provisional is your priority date.