What is the significance of the “effective filing date” in AIA public use determinations?

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 determining whether a public use qualifies as prior art under the AIA. The MPEP states:

“[A] public use would need to occur before the effective filing date of the claimed invention to constitute prior art under AIA 35 U.S.C. 102(a)(1).”

This means that any public use that occurs on or after the effective filing date cannot be used as prior art against the patent application. The effective filing date is typically the earliest of:

• The actual filing date of the patent application
• The filing date of the earliest priority application to which the patent application is entitled

It’s important to note that this differs from the pre-AIA system, which used a “critical date” one year prior to the U.S. filing date. The AIA’s focus on the effective filing date can potentially provide more protection for inventors who file promptly after public disclosure or use.