Is designating a domestic representative mandatory for foreign patent assignees?

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.

While designating a domestic representative is not mandatory, it is highly recommended for foreign patent assignees. According to MPEP 302.04, An assignee of a patent or patent application who is not domiciled in the United States may, by written document signed by such assignee, designate a domestic representative. The use of ‘may’ indicates that this is optional. However, having a domestic representative can significantly simplify legal proceedings and communications with the USPTO for foreign assignees.