Section 39-21-107 - [Effective 7/1/2025] Limitations(1) Except as provided in this section, in section section 29-2-208 (2)(a)(III), and section 29-2-302 (5)(b), and unless such time is extended by waiver, the amount of any tax or of any charge on oil and gas production, and the penalty and interest applicable to the tax or charge, shall be assessed within three years after the return was filed, whether or not such return was filed on or after the date prescribed, and no assessment shall be made or credit taken and no notice of lien shall be filed, nor distraint warrant issued, nor suit for collection instituted, nor any other action to collect the same commenced after the expiration of such period; except that a written proposed adjustment of the tax liability by the department issued prior to the expiration of such period shall extend the limitation of this subsection (1) for one year after a final determination or assessment is made. No lien shall continue after the three-year period provided for in this subsection (1), except for taxes assessed before the expiration of such period, notice of lien with respect to which has been filed prior to the expiration of such period, and except for taxes on which written notice of any proposed adjustment of the tax liability has been sent to the taxpayer during such three-year period, in which case the lien shall continue for one year only after the expiration of such period or after the issuance of a final determination or assessment based on the proposed adjustment issued prior to the expiration of the three-year period. This subsection (1) does not apply to income tax or to any tax imposed under article 23.5 of this title 39.(2) In the case of an income tax imposed by article 22 of this title 39, unless such time is extended by waiver and except as provided in subsection (2.5) of this section, section 39-22-601 (6)(e), and section 39-22-601.5, the assessment of any tax, penalties, and interest shall be made within one year after the expiration of the time provided for assessing a deficiency in federal income tax or changing the reported federal taxable income of a partnership, limited liability company, or fiduciary; except that a written proposed adjustment of the tax liability by the department must extend the limitation of this subsection (2) for one year after a final determination or assessment is made. An assessment of income taxes having been made according to law must be good and valid and collection thereof may be enforced at any time within six years from the date of said assessment.(2.5) Any limitations applicable to taxes, penalties, interest, fines, or charges within the scope of this article 21, as set forth in section 39-21-102, are suspended: (a) For any period during which the taxpayer's assets are in the control or custody of a court in any proceeding before any court of the United States or any state, and for six months thereafter; or(b) For any period during which the department is prohibited from collecting by reason of a case under title 11 of the United States Code, and for six months thereafter.(3) For purposes of this section, a tax return filed before the last day prescribed by law or by regulation promulgated pursuant to law for the filing thereof shall be considered as filed on such last day.(4) In the case of failure to file a return or the filing of a false or fraudulent return with intent to evade tax, the tax may be assessed and collected at any time.(5) Where, before the expiration of the time prescribed in this section for the assessment of tax, both the executive director of the department of revenue or his delegate and the taxpayer have consented in writing to an assessment after such time, the tax may be assessed at any time prior to the expiration of the period agreed upon. The period so agreed upon may be extended by subsequent agreements in writing made before the expiration of the period previously agreed upon.(6) Nothing in this section shall be construed to limit any right accrued or revive any liability barred by any statute enacted on or before July 1, 1965.Amended by 2024 Ch. 423,§ 10, Proposition KK passed by voters in 11/5/2024 election, eff. upon official declaration by the governor, 12/17/2024.Amended by 2024 Ch. 144,§ 39, eff. 7/1/2025, app. to any taxable event occurring on or after 7/1/2025.Amended by 2024 Ch. 184,§ 8, eff. 5/16/2024.Amended by 2023 Ch. 290,§ 4, eff. 8/7/2023.Amended by 2019 Ch. 64, § 1, eff. 8/2/2019.L. 65: p. 1136, § 2. C.R.S. 1963: § 138-9-6. L. 73: p. 1417, § 102. L. 77: (2) amended, p. 1770, § 1, effective May 18; (1) amended, pp. 1767, 1853, §§ 4, 6, effective 1/1/1978. L. 79: (1) amended, p. 1500, § 23, effective 1/1/1980. L. 83: (1) and (2) amended, p. 1510, § 1, effective May 26. L. 86: (1) amended, p. 1110, § 6, effective July 1. L. 89: (1) amended, p. 1594, § 7, effective 7/1/1993. L. 90: (2) amended, p. 450, § 29, effective April 18; (1) amended, p. 1722, § 7, effective May 1; (1) amended, p. 1723, § 8, effective 7/1/1993. L. 92: (1) amended, p. 2247, § 1, effective July 1. L. 2001: (1) amended, p. 778, § 10, effective June 1. L. 2002: (1) amended, p. 1361, § 16, effective July 1. L. 2009: (1) amended, (HB 09-1053), ch. 690, p. 690, § 13, effective August 5. L. 2017: (1) amended, (SB 17-112), ch. 483, p. 483, § 3, effective April 18. L. 2019: (2) amended and (2.5) added, (SB 19 -035), ch. 230, p. 230, § 1, effective August 2.(1) Amendments to subsection (1) by Senate Bill 77-144 and House Bill 77-1076 were harmonized.
(2) Amendments to subsection (1) by SB 24-025 and SB 24-230 were harmonized, effective July 1, 2025.
(3) Subsection (1) was amended in HB 24-1349, which was to take effect only if a majority of voters approved the ballot issue referred in accordance with § 39-37-201. However, those amendments in HB 24-1349 were superseded by the amendment of subsection (1) in SB 24-230, effective May 16, 2024.
(4) Section 54 of chapter 144 (SB 24-025), Session Laws of Colorado 2024, provides that the act changing this section applies to any taxable event occurring on or after July 1, 2025.
2023 Ch. 290, was passed without a safety clause. See Colo. Const. art. V, § 1(3).This section is set out more than once due to postponed, multiple, or conflicting amendments.