What is the significance of the effective filing date in patent examination?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The effective filing date plays a crucial role in patent examination for several reasons:

• It determines the cutoff date for prior art that can be used against the claimed invention.
• It establishes the date from which the claimed invention is entitled to priority.
• It affects the applicability of certain AIA provisions, such as the grace period.

According to MPEP 2152.01:

“The AIA defines the term ‘effective filing date’ for a claimed invention in a patent or application for patent (other than a reissue application or reissued patent) as the earliest of: (1) the actual filing date of the patent or the application for the patent containing the claimed invention; or (2) the filing date of the earliest application for which the patent or application is entitled to claim a right of priority or the benefit of an earlier filing date under 35 U.S.C. 119, 120, 121, 365, or 386.”

This definition underscores the importance of the effective filing date in determining the scope of prior art and the applicability of various AIA provisions during patent examination.