Any person who wilfully makes or subscribes to a claim for refund under this article which he does not believe to be true and correct as to every material matter, shall be guilty of a felony, and upon conviction thereof shall be subject to the penalties prescribed for perjury by the Penal Code.
Source:
Section 8103.5, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC§ionNum=8103.5..