Source: L. 65: p. 1137, § 2. C.R.S. 1963: § 138-9-7. L. 67: pp. 847, 848, §§ 1, 2. L. 71: p. 1265, § 1. L. 77: (1)(a) amended and (4) added, pp. 1767, 1853, §§ 5, 7, effective January 1, 1978. L. 82: (3) amended, p. 558, § 1, effective April 6. L. 83: (3) amended, p. 794, § 5, effective June 3; (3) amended, p. 654, § 2, effective June 10; (3) amended, p. 438, § 2, effective June 15. L. 84: (3)(a) amended and (3)(b)(IV) added, pp. 1008, 1010, §§ 3, 4, effective March 29; (3) amended, p. 1011, § 1, effective April 27; (3)(b)(IV) repealed and (3)(b) amended, pp. 1125, 1126, §§ 47, 48, effective June 7. L. 85: (3)(a)(I), (3)(a)(VI), and (3)(b) amended, p. 1366, § 39, effective June 28; (3)(a)(I), (3)(a)(III), and (3)(b) amended, p. 602, § 22, effective July 1. L. 88: (3)(a)(I) amended, p. 637, § 19, effective July 1. L. 89: (3)(a)(I) and (3)(b) amended and (3)(a)(VII) added, p. 1195, § 4, effective June 7; (3)(a)(I) amended, p. 799, § 34, effective July 1; (1)(a) amended, p. 1595, § 8, effective July 1, 1993. L. 94: (3)(a)(I), (3)(a)(III), and (3)(a)(VII) amended, p. 3135, § 299, effective July 1. L. 96: (1)(a) amended, p. 164, § 4, effective July 1. L. 98: (3)(a)(II) amended, p. 91, § 5, effective March 23. L. 98, 2nd Ex. Sess.: (3)(a)(I) amended, p. 7, § 4, effective September 16. L. 99: (3)(a)(I) amended, p. 1317, § 5, effective August 4. L. 2001: (1)(a) and (3)(a)(I) amended, p. 778, § 11, effective June 1; (1)(a) amended, p. 233, § 2, effective August 8; (5) added, p. 619, § 4, effective August 8. L. 2002: (3)(a)(I) amended, p. 99, § 1, effective August 7. L. 2004: (1)(a) amended, p. 383, § 2, effective April 8; (3)(a)(I) amended, p. 576, § 35, effective July 1; (1)(b) repealed, p. 207, § 31, effective August 4; (3)(a)(I)(A) and (3)(b) amended and (3)(a)(VIII) added, p. 1259, § 4, effective August 4; (6) added, p. 315, § 3, effective August 4. L. 2009: (1)(a) and (3)(a)(I)(A) amended, (HB 09-1053), ch. 159, p. 690, § 14, effective August 5; (3)(a)(III), (3)(a)(IV), (3)(a)(V), and (3)(a)(VI) amended, (HB 09-1137), ch. 308, p. 1662, § 14, effective September 1. L. 2010: (6) repealed, (SB 10-212), ch. 412, p. 2032, § 1, effective July 1; (7) added, (SB 10-186), ch. 309, p. 1454, § 1, effective August 11. L. 2011: (1)(a) amended, (HB 11-1303), ch. 264, p. 1175, § 91, effective August 10. L. 2012: (3)(a)(I)(A) amended, (HB 12-1120), ch. 27, p. 112, § 31, effective June 1. L. 2013: (3)(a)(I)(A) amended, (SB 13-247), ch. 296, p. 1584, § 4, effective August 7. L. 2014: (3)(a)(I)(A) amended, (SB 14-019), ch. 10, p. 96, § 2, effective February 27. L. 2019: (5)(a) and (7)(a) amended, (SB 19-088), ch. 110, p. 470, § 18, effective July 1, 2020. L. 2021: (3)(a)(I)(A) and (3)(a)(V) amended, (SB 21-055), ch. 12, p. 78, § 15, effective March 21.
Cross references: For the legislative declaration contained in the 2001 act amending subsection (1)(a), see section 1 of chapter 95, Session Laws of Colorado 2001.
Structure Colorado Code
Article 21 - Procedure and Administration
§ 39-21-104. Rejection of Claims
§ 39-21-104.5. Frivolous Submissions
§ 39-21-105.5. Notice - First-Class Mail - Definition
§ 39-21-109. Interest on Underpayment, Nonpayment, or Extensions of Time for Payment of Tax
§ 39-21-110. Interest on Overpayments
§ 39-21-110.5. Rate of Interest to Be Fixed
§ 39-21-111. Jeopardy Assessment and Demands
§ 39-21-112. Duties and Powers of Executive Director
§ 39-21-113. Reports and Returns - Rule
§ 39-21-114. Methods of Enforcing Collection
§ 39-21-114.5. Surrender of Property Subject to Levy - Definition
§ 39-21-115. Reciprocity With Other States for Collection of Taxes Provided
§ 39-21-116. Closing Agreements
§ 39-21-116.5. Penalties - Repeal
§ 39-21-118. Criminal Penalties - Repeal
§ 39-21-119. Filing With Executive Director - When Deemed to Have Been Made
§ 39-21-120. Signature and Filing Alternatives for Tax Returns