How does claiming benefit to a provisional application affect the effective filing date?

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.

Claiming benefit to a provisional application can affect the effective filing date of a claimed invention as follows:

If the application properly claims benefit under 35 U.S.C. 119(e) to a provisional application, the effective filing date of a claimed invention is the filing date of the provisional application for any claims which are fully supported under 35 U.S.C. 112 by the provisional application.

This means that:

• Claims fully supported by the provisional application can have the provisional’s filing date as their effective filing date.
• The support must meet the requirements of 35 U.S.C. 112, including written description and enablement.
• Claims not fully supported by the provisional will have a later effective filing date, typically the actual filing date of the non-provisional application.

Properly claiming benefit to a provisional application can provide an earlier effective filing date, which can be crucial for establishing priority and overcoming prior art.