Cal. Rev. & Tax. Code § 23181

(a) Except as otherwise provided herein, an annual tax is hereby imposed upon every bank doing business within the limits of this state according to or measured by its net income, upon the basis of its net income for the next preceding income year at the rate provided under Section 23186.
(b) If a bank commences to do business and ceases doing business in the same taxable year, the tax for such taxable year shall be according to or measured by its net income for such year, at the rate provided under Section 23186.
(c) With respect to a bank, other than a bank described in subdivision (b), which ceases doing business after December 31, 1972, the tax for the taxable year of cessation shall be:
1. (1) According to or measured by its net income for the next preceding income year, to be computed at the rate prescribed in Section 23186, plus
2. (2) According to or measured by its net income for the income year during which the bank ceased doing business, to be computed at the rate prescribed in Section 23186.
(d) In the case of a bank which ceased doing business before January 1, 1973, but dissolves or withdraws on such date or thereafter, the tax for the taxable year of dissolution or withdrawal shall be according to or measured by its net income for the income year during which the bank ceased doing business, unless such income has previously been included in the measure of tax for any taxable year, to be computed at the rate prescribed under Section 23186 for the taxable year of dissolution or withdrawal.
(e) Commencing with income years ending in 1980, every bank shall pay to the state a minimum tax (determined in accordance with Section 23153) or the measured tax imposed on its income, whichever is greater.
(f)
1. (1) For the first taxable year beginning on or after January 1, 2000, the tax imposed under this section shall be the sum of both of the following:
  1. (A) A tax according to or measured by net income, to be computed at the rate provided under Section 23186 upon the basis of the net income for the next preceding income year, but not less than the minimum tax specified in Section 23153.
  2. (B) A tax according to or measured by net income, to be computed at the rate provided under Section 23186 upon the basis of the net income for the first taxable year beginning on or after January 1, 2000, but not less than the minimum tax specified in Section 23153.
2. (2) Except as provided in paragraph (1), for taxable years beginning on or after January 1, 2000, the tax imposed under this section shall be a tax according to or measured by net income, to be computed at the rate provided under Section 23186 upon the basis of the net income for that taxable year, but not less than the minimum tax specified in Section 23153.