California Code, Penal Code - PEN § 18121

There is no filing fee for an application, a responsive pleading, or an order to show cause that seeks to obtain, modify, or enforce a gun violence restraining order or other order authorized by this division if the request for the other order is necessary to obtain or give effect to a gun violence restraining order or other order authorized by this division. There is no fee for a subpoena filed in connection with that application, responsive pleading, or order to show cause.There is no fee for any filings related to a petition filed pursuant to this division.