Cal. Rev. & Tax. Code § 19151

Notwithstanding Sections 19142 to 19150, inclusive, the addition to the tax with respect to underpayment of any installment shall not be imposed on an exempt organization described in Section 23731 whose exemption is retroactively revoked unless the organization described in Section 23731 has notice that the estimated tax should have been paid. The denial of the organization’s exemption application or the revocation of its exemption by the Internal Revenue Service normally satisfies the notice requirement.