What is interference practice in patent law?

Interference practice is a procedure used to determine priority of invention between two parties. It is based on pre-AIA 35 U.S.C. 102(g). As stated in the MPEP:

“An interference is an inter partes proceeding directed at determining the first to invent as among the parties to the proceeding, involving two or more pending applications naming different inventors or one or more pending applications and one or more unexpired patents naming different inventors.”

This process is unique to the U.S. patent system, which has historically operated on a first-to-invent basis rather than a first-to-file system for certain applications.

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Topics: MPEP 2100 - Patentability, MPEP 2138.01 - Interference Practice, Patent Law, Patent Procedure
Tags: first-to-invent, interference, patent applications, Priority Of Invention