63-3024. (1) For each taxable year, a tax measured by Idaho taxable income as defined in this chapter is hereby imposed upon every individual, trust, or estate required by this chapter to file a return.(2)(a) The tax imposed upon individuals, trusts, and estates shall be computed at the rate of five and three-tenths percent (5.3%) of taxable income over two thousand five hundred dollars ($2,500).(b) For taxpayers filing a joint return pursuant to the provisions of section 63-3031, Idaho Code, the tax imposed shall be computed at the rate of five and three-tenths percent (5.3%) of taxable income over five thousand dollars ($5,000). For the purposes of this section, a return of a surviving spouse, as defined in section 2(a) of the Internal Revenue Code, and a head of household, as defined in section 2(b) of the Internal Revenue Code, shall be treated as a joint return.(3) For taxable year 2000 and each year thereafter, the state tax commission shall prescribe a factor that shall be used to compute the Idaho income tax thresholds provided in subsection (2) of this section. The factor shall provide an adjustment to the Idaho tax thresholds so that inflation will not result in a tax increase. The Idaho tax thresholds shall be adjusted as follows: multiply the last threshold amount by the percentage (the consumer price index for the calendar year immediately preceding the calendar year to which the adjusted threshold amount will apply divided by the consumer price index for calendar year 1998). For the purpose of this computation, the consumer price index for any calendar year is the average of the consumer price index as of the close of the twelve (12) month period for the immediately preceding calendar year, without regard to any subsequent adjustments, as adopted by the state tax commission. This adoption shall be exempt from the provisions of chapter 52, title 67, Idaho Code. The consumer price index shall mean the consumer price index for all U.S. urban consumers published by the United States department of labor. The state tax commission shall annually include the factor as provided in this subsection to multiply against Idaho taxable income using the thresholds in this section to arrive at that year’s Idaho taxable income for tax threshold purposes.(4) In the case of a trust that is an electing small business trust as defined in section 1361 of the Internal Revenue Code, the special rules for taxation of such trusts contained in section 641 of the Internal Revenue Code shall apply, except that the individual rate provided in subsection (2)(a) of this section shall apply in computing tax due under this chapter.(5) The state tax commission may promulgate rules defining the conditions upon which such returns shall be filed.
Amendment history
63-3024, added 2022, 1st E.S., ch. 1, sec. 5, p. 6; am. 2024, ch. 237, sec. 2, p. 824; am. 2025, ch. 13, sec. 3, p. 43.