Statutes and regulations

§ 39-21-109, C.R.S. Interest on underpayment, non-payment, or extensions of time for payment of tax.

§ 39-21-110.5, C.R.S. Rate of interest to be fixed.

§ 39-21-113, C.R.S. Reports and returns – rule.

§ 39-21-119, C.R.S. Filing with executive director – when deemed to have been made.

§ 39-21-120, C.R.S. Signature and filing alternatives for tax returns.

§ 39-22-107, C.R.S. Income tax filing status.

§ 39-22-107.5, C.R.S. Income tax filing status – innocent spouse relief.

§ 39-22-111, C.R.S. Accounting periods and methods.

§ 39-22-601, C.R.S. Returns.

§ 39-22-608, C.R.S. Form, place, and date of filing return – extension – electronic filing.

§ 39-22-609, C.R.S. Payment of tax – applicable when.

§ 39-22-621, C.R.S. Interest and penalties.

Rule 39-21-120. Signature and filing alternatives.

Rule 39-22-608. Due date for filing income tax returns and payments.

Rule 39-22-621.2(j).