How is correspondence addressed in PCT applications with multiple applicants?

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 MPEP provides guidance on addressing correspondence in PCT applications with multiple applicants:

• If there’s a common agent appointed, correspondence is addressed to that agent or the first-mentioned agent.
• If no common agent is appointed, correspondence is addressed to the common representative at their indicated address.
• If the common representative has appointed agents, correspondence goes to that agent or the first-mentioned agent.

The MPEP 1834 states: “Where there are two or more applicants who have appointed one or more common agents, correspondence will be addressed to that agent or the first-mentioned of those agents. Where no common agent has been appointed, correspondence will be addressed to the common representative.”