Can a power of attorney be signed by less than all applicants or owners of a patent application?

Generally, a power of attorney must be signed by all applicants or owners of a patent application. However, there are exceptions:

1. For revocation: A power of attorney signed by less than all applicants/owners may be accepted if accompanied by a petition under 37 CFR 1.36(a) and fee, with a showing of sufficient cause.
2. For appointment: A power of attorney signed by less than all applicants/owners may be accepted if accompanied by a petition under 37 CFR 1.183 and fee, demonstrating an extraordinary situation where justice requires waiver of the requirement.

MPEP 402.10 states: “The appointment and/or revocation are not accepted until the petition under 37 CFR 1.36(a) or 1.183 is granted. Therefore, the attorney or agent newly appointed by such papers is not permitted to submit any documents (such as an information disclosure statement (IDS)) into the application file until the petition under 37 CFR 1.36(a) or 1.183 is granted.”