Cal. INS § 1530

In lieu of all other taxes, licenses or fees whatever, state or local, each exchange and its corporate attorney in fact considered as a single unit shall together pay annually on account of the transaction of such business in this state, the same fees as are paid by mutual insurers transacting the same kind of business, and the annual tax imposed by Section 28 of Article XIII of the Constitution of the State of California and by the applicable provisions of the Revenue and Taxation Code, except that each corporate attorney in fact of a reciprocal or interinsurance exchange shall be subject to all taxes imposed upon other corporations doing business in the state, other than taxes directly attributable to property used exclusively in or on income derived from its principal business as corporate attorney in fact. In any event, such corporate attorney in fact shall file an annual return and pay the minimum tax provided for by Section 23151 of the Bank and Corporation Tax Law. For the purposes of Section 12221 of the Revenue and Taxation Code, the term gross premiums, as applied to reciprocal or interinsurance exchanges, includes all sums paid by subscribers in this state by reason of the insurance exchange, whether termed premium deposit, membership fee, or otherwise, after deducting therefrom premium deposit returns or cancellations, and all amounts returned to subscribers or credited to their accounts as savings, but does not include such sums received for reinsurance and for ocean marine insurance.

A corporate attorney in fact of each exchange shall annually compute the amount of tax that would be payable by it under the provisions of the Bank and Corporation Tax Law (Part 11 (commencing with Section 23001) of Division 2 of the Revenue and Taxation Code) except for the provisions of this section, and any management fee due from each exchange to its corporate attorney in fact shall be reduced pro tanto by a sum equivalent to the amount so computed.