Cal. Rev. & Tax. Code § 17049

(a) If an item of income was included in the gross income of an individual for a preceding taxable year or years because it appeared that the individual had an unrestricted right to that item, a deduction is allowable for the taxable year based on the repayment of the item by the individual during the taxable year, and the amount of that deduction exceeds three thousand dollars ($3,000), then the tax imposed by this part for the taxable year on that individual shall be the lesser of the following:
1. (1) The tax for the taxable year computed with that deduction.
2. (2) An amount equal to (A) the tax for the taxable year computed without that deduction, minus (B) the decrease in tax under this part for the preceding taxable year or years which would result solely from the exclusion of the item or portion thereof from the gross income required to be shown on the California return of that individual for the preceding taxable year or years.
(b) If the decrease in tax determined under subparagraph (B) of paragraph (2) of subdivision (a) for the preceding taxable year or years exceeds the tax imposed for the taxable year, computed without the deduction, that excess shall be considered to be a payment of tax on the last day prescribed for the payment of tax for the taxable year, and shall be refunded or credited in the same manner as if it were an overpayment for the taxable year.
(c) Subdivision (a) does not apply to any deduction allowable with respect to an item which was included in gross income by reason of the sale or other disposition of stock in trade of the taxpayer, or other property of a kind which would properly have been included in the inventory of the taxpayer if on hand at the close of the prior taxable year, or property held by the taxpayer primarily for sale to customers in the ordinary course of his or her trade or business.
(d) If the tax imposed by this part for the taxable year is the amount determined under paragraph (2) of subdivision (a), then the deduction referred to in subdivision (a) shall not be taken into account for any purpose of this part, or Part 10.2 (commencing with Section 18401), other than this section.
(e) For purposes of determining whether paragraph (1) or paragraph (2) of subdivision (a) applies, in any case where the exclusion referred to in subparagraph (B) of paragraph (2) of subdivision (a) results in a net operating loss or capital loss for the prior taxable year, or years, that loss shall, for purposes of computing the decrease in tax for the prior taxable year, or years, under subparagraph (B) of paragraph (2) of subdivision (a), be carried over to the same extent and in the same manner as is provided under Section 17276, 17276.1, 17276.2, 17276.4, 17276.5, or 17276.7, or Section 1212 of the Internal Revenue Code, as applicable for California purposes, except that no carryover beyond the taxable year shall be taken into account.
(f) For purposes of this part, the net operating loss or capital loss described in subdivision (e) shall, after the application of paragraph (1) or (2) of subdivision (a) for the taxable year, be taken into account under Section 17276, 17276.1, 17276.2, 17276.4, 17276.5, or 17276.7, or Section 1212 of the Internal Revenue Code, as applicable for California purposes, for taxable years after the taxable year to the same extent and in the same manner as either of the following:
1. (A) A net operating loss sustained for the taxable year, if paragraph (1) of subdivision (a) applied.
2. (B) A net operating loss or capital loss sustained for the prior taxable year, or years, if paragraph (2) of subdivision (a) applied.
(g) Regulations promulgated by the Secretary of the Treasury under Section 1341 of the Internal Revenue Code shall apply, except to the extent that those regulations conflict with this section, provisions of this part, or with regulations promulgated by the Franchise Tax Board.