Rev. & Tax. Code, § 24636

(a) If a separate return is made by a taxpayer subject to the tax imposed by Chapter 2, under Section 24634 on account of a change in the accounting period the net income, computed on the basis of the period for which the separate return is made, referred to in this section as “the short period,” shall be placed on an annual basis by multiplying the amount thereof by 12, and dividing by the number of months in the short period. The Franchise Tax Board shall compute the amount of a tax on the income placed on such annual basis, and shall allow the offset provided for in Article 3 of Chapter 2, from such tax. The tax due under this section, which shall not be subject of offset, shall be such part of the tax, less the offset allowed, computed on such annual basis as the number of months in the short period is of 12 months.

(b) If a taxpayer subject to the tax imposed by Chapter 2 establishes the amount of its net income for the period of 12 months beginning with the first day of the short period, computed as if such 12-month period were a taxable year, under the law applicable to such year, then the tax for the short period shall be reduced to an amount which is such part of the tax computed on the net income for such 12-month period as the net income computed on the basis of the short period is of the net income for the 12-month period. The taxpayer (other than a taxpayer to which the next sentence applies) shall compute the tax and file its return without the application of this section. If the taxpayer has disposed of substantially all its assets prior to the end of such 12-month period, then in lieu of the net income for such 12-month period there shall be used for the purposes of this section the net income for the 12-month period ending with the last day of the short period. The tax computed under this section shall in no case be less than the tax computed on the net income for the short period without placing such net income on an annual basis. The benefits of this section shall not be allowed unless the taxpayer, at such time as regulations prescribed hereunder require (but not after the time prescribed for the filing of the return for the first taxable year which ends on or after 12 months after the beginning of the short period), makes application therefor in accordance with such regulations. Such application, in case the return was filed without regard to this section, shall be considered a claim for credit or refund with respect to the amount by which the tax is reduced under this section. The Franchise Tax Board shall prescribe such regulations as it may deem necessary for the application of this section.

(c) In the case of a taxpayer required to file a short period return pursuant to Section 24634, the alternative minimum tax shall be determined in accordance with Section 443(d) of the Internal Revenue Code.