California Code of Civil Procedure Section 367
Code of Civil Procedure section 367 requires that "every action must be prosecuted in the name of the real party in interest."
The real party in interest is a person "'who has the right to sue under the substantive law. It is the person who owns or holds title to the claim or property involved, as opposed to others who may be interested or benefited by the litigation.' " (O'Flaherty v. Belgum (2004) 115 Cal.App.4th 1044, 1094.)
"A complaint filed by someone other than the real party in interest is subject to general demurrer on the ground that it fails to state a cause of action." (Redevelopment Agency of City of San Diego v. San Diego Gas & Electric Co. (2003) 111 Cal.App.4th 912, 921.)