Cal. Code Regs. tit. 18 § 15653.1
A return made by a donor's agent is not sufficient unless the donor is unable to make the return himself within the required time by reason of illness or absence from the State. Mere convenience is not sufficient reason for authorizing an agent to make the return. If by reason of illness or absence from the State a return is made by an agent, such return must be ratified within a reasonable time by the donor. The ratification must be in the form of an affidavit, or declaration executed under penalty of perjury, filed with the State Controller, and must specifically state that the return made by the agent has been carefully examined and that the affiant ratifies the return as his own.
NOTE: Reference: Section 15653, Revenue and Taxation Code.
Cal. Code Regs. Tit. 18, § 15653.1