Cal. Rev. & Tax. Code § 25103

In the case of a corporation doing business within the meaning of this part, whether under agreement or otherwise, in such manner as either directly or indirectly to benefit the members or stockholders of the corporation, or any of them, or any person or persons, directly or indirectly interested in such business, by rendering services of any nature whatsoever, or acquiring or disposing of its products or the goods or commodities in which it deals, at less than a fair price therefore, the Franchise Tax Board, in order to prevent evasion of taxes or clearly to reflect the income of such corporation, may require a report of such facts as it deems necessary, and may determine the amount which shall be deemed to be the entire net income allocable to this State of the business of such corporation for the calendar or fiscal year, and compute the tax upon such net income. In determining the entire net income the Franchise Tax Board shall have regard to the fair profits which, but for any agreement, arrangement, or understanding, might be or could have been obtained from dealing in such products, goods or commodities.