An interference proceeding, also known as priority contest, is an inter partes proceeding to determine the priority issues of multiple patent applications. It is a patent law concept unique to the United States. Unlike most other countries that have adopted the first-to-file system, the first-to-invent system of the U.S. allows a party that failed to file a patent application on time to challenge the inventorship of another party that has a granted or pending patent if certain requirements are met. The interference proceeding is an administrative proceeding conducted by a panel of Administrative Patent Judges (administrative law judges sitting on the Board of Patent Appeals and Interferences) of the United States Patent and Trademark Office (USPTO) to determine which applicant is not entitled to the patent if both claim the same invention in two or more pending patent applications, or at least one pending patent application and at least one patent issued within a year of the pending application's filing date.

We counsel clients in all areas of interferences, including claim strategies to avoid, narrow or win an interference and to affect a competitors patent prosecution. We provide advice on proper invention record keeping to prove date of invention, proper timing for considering interference issues, and provoking or avoiding interferences.

We have experience in prosecuting interferences from declaration through final hearing, as well as settlement and licensing negotiations and agreements. We have the ability to use U.S. Patent and Trademark Office procedures to the client's advantage and provide strategies for working with Interference Practice Specialists. We can also support our clients' needs in appeals to the Court of Appeal for the Federal Circuit, as well as Section 146 appeals to U.S. District Courts.