Why are ex parte communications prohibited in patent interferences?

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.

Ex parte communications are prohibited in patent interferences to maintain the fairness and integrity of the proceedings. The MPEP 2307.01 explains:

“Since an interference involves two or more parties, the integrity of the process requires the opportunity for the opposing party to participate in communications or actions regarding any involved application or patent.”

This prohibition ensures that all parties have equal access to information and prevents any unfair advantage. It also maintains transparency in the process and upholds the adversarial nature of interference proceedings, where both parties should have the opportunity to respond to all communications and actions related to the case.