Good cause. Except as noted, the taxpayer must make an affirmative showing of all facts in order to prove good cause.
Returns filed under extension: The failure to file penalty described in C.R.S. 39-22-621(2)(a) will not be due if a taxpayer files his or her tax return within the extension period.
Unless specifically waived by the Department for good cause, the failure to pay penalty described in C.R.S. 39-22-621(2)(b) will be due if:
(1) the taxpayer has not paid at least ninety percent of his or her net tax liability into the Department of Revenue as of the original due date of the return, or(2) the taxpayer does not file by the extension due date, or(3) the taxpayer does not pay all of the net tax due with the taxpayer's filed return.Interest will be assessed on any net tax liability due with a return filed under extension, for the period from the original due date until payment is made.
Net tax liability means the total Colorado income tax liability for the tax year reduced by all credits other than prepayment credits.
Prepayment credits are credits for income tax paid by the taxpayer (including income tax withheld from the taxpayer's wages) before the original due date of the return.
Colorado Register, Vol 37, No. 14. July 25, 2014, effective 8/14/201437 CR 18, September 25, 2014, effective 10/15/201437 CR 19, October 10,2014, effective 10/30/201437 CR 22, November 25, 2014, effective 12/16/201438 CR 04, February 25, 2015, effective 3/17/201538 CR 07, April 10, 2015, effective 4/30/201538 CR 11, June 10, 2015, effective 6/30/201538 CR 22, November 25, 2015, effective 12/15/201538 CR 24, December 25, 2015, effective 1/14/201638 CR 24, December 25, 2015, effective 1/19/201639 CR 01, January 10, 2016, effective 1/30/201639 CR 16, August 25, 2016, effective 9/14/201640 CR 08, April 25, 2017, effective 5/15/201740 CR 12, June 25, 2017, effective 7/15/201740 CR 16, August 25, 2017, effective 9/14/201740 CR 23, December 10, 2017, effective 1/1/201841 CR 14, July 25, 2018, effective 8/14/201841 CR 20, October 25, 2018, effective 11/14/201842 CR 02, January 25, 2019, effective 12/18/201842 CR 02, January 25, 2019, effective 12/18/2018, expires 4/17/201942 CR 06, March 25, 2019, effective 4/14/201943 CR 04, February 25, 2020, effective 3/16/202043 CR 13, July 10, 2020, effective 6/2/202043 CR 17, September 10, 2020, effective 9/30/202044 CR 03, February 10, 2021, effective 3/2/202144 CR 07, April 10, 2021, effective 4/30/202144 CR 08, April 25, 2021, effective 5/15/202145 CR 01, January 10, 2022, effective 1/30/202245 CR 04, February 25, 2022, effective 3/17/202245 CR 05, March 10, 2022, effective 3/30/202246 CR 11, June 10, 2023, effective 5/2/202346 CR 09, May 10, 2023, effective 5/30/2023 Extension of time to file return: C.R.S. 39-22-608(2), Rule 39-22-608(2)(b) Interest: C.R.S. 39-22-621(1) The taxpayer must make an affirmative showing of all facts alleged in order to prove reasonable cause.