Revenue and Taxation Code § 23223

(a) When any taxpayer commences to do business in this state for the first time in any taxable year other than the year of incorporation or qualification, its tax for that taxable year and for the succeeding taxable year shall be computed in accordance with the provisions of Section 23222 relative to first and second taxable years, a credit being allowed for any tax payable under Section 23153 for the year in which it commences to do business.

(b) The provisions of subdivision (a) shall be applicable only if a taxpayer commenced doing business in this state before January 1, 1972.