Cal. RTC § 531.1

Upon the termination of an exemption pursuant to Section 271.5 or 276.3, upon receipt of a notice pursuant to Section 284, or upon indication from any audit or other source that an exemption has been incorrectly allowed, the assessor shall make a redetermination of eligibility for the exemption. If an exemption or any portion of an exemption has been terminated or has been incorrectly allowed, an escape assessment in the amount of the exemption, or that portion of the exemption that has been terminated or erroneously allowed, with interest as provided in Section 506, shall be made; except that where the exemption was terminated pursuant to Section 271.5 or 276.3 or where the exemption or a portion of the exemption was allowed as the result of an assessor’s error, the amount of interest shall be forgiven. If the exemption was incorrectly allowed because of erroneous or incorrect information submitted by the claimant with knowledge that the information was erroneous or incomplete, the penalty provided in Section 504 shall be added to the assessment.