Important Assessment Dates

Important dates for taxpayers according to Colorado law.
Date Task Statute (Law)
January 1 Assessment date for all taxable property. 39-1-105
As soon after January 1 as possible Assessor mails or delivers one personal property schedule and two subdivision land valuation questionnaires to appropriate taxpayers.  39-5-108 39-1-103(14)(d) 
Not later than January 10 Assessor delivers tax warrant to treasurer. 39-5-129
Not later than March 20 Subdivision developers or agents must return signed, completed questionnaires to assessor.  39-1-103(14)(d) 
Not later than
April 15 
Taxpayers return personal property schedules to assessor, including works of art display statement.
39-5-108 39-5-113.5(1) 
Not later than
April 15 
Taxpayers may request extension of 10 or 20 days for filing personal property schedule.  39-5-116(1) 
Subsequent to
April 15
Assessor determines personal property values from best information available and imposes a penalty for taxpayers failing to file.
On or before
May 1 
Assessor gives public notice of hearings on real and personal property. 39-5-122(1)
Not later than May 1 Assessor sends Notices of Valuation (NOV) for real property, together with a protest form to taxpayers.  Sec. 20, Art X, CO Constitution 39-5-121(1) 39-7-102.5 
Beginning on first working day after NOVs are mailed Assessor sits to hear objections concerning real property valuations. 39-5-122(1)
Not later than
June 8
Taxpayer physically delivers or mails real property protest to assessor (postmarked no later than June 8).  39-5-121(1) 39-5-122(1) ,(2)
By June 8 Assessor concludes real property hearings.  39-5-122(1),(4) 
Not later than
June 15
Assessor sends NOVs, together with a protest form, for personal property to taxpayer. 
Sec. 20, Art. X, CO Constitution 39-5-121(1.5) 39-5-113.3(2) 39-7-102.5 
Beginning on
June 15
Assessor sits to hear all objections concerning personal property valuations. (2020 ONLY - changed to August 3)
39-5-122(1) 39-7-102.5 
Not later than
June 30
Taxpayer mails or hand delivers personal property protest to assessor (postmarked no later than June 30). 
39-5-121(1.5) 39-5-122 
On or before last working day in June Assessor mails two copies of real property Notice of Determination (NOD) to taxpayer.  39-5-122(2) 
Beginning on
July 1
County Board of Equalization (CBOE) sits to hear appeals on real and personal property valuations. 39-8-104 
By July 5 Assessor concludes personal property hearings.
On or before
July 10 
Assessor mails two copies of personal property NOD to taxpayer.
On or before
July 15 of that year 
Taxpayer mails one copy of assessor's real property NOD to CBOE. (Appeals bearing postmark on or before July 15 constitute proper filing.)  39-8-106(1)(a) 
On or before
July 20 of that year 
Taxpayer mails one copy of assessor's personal property NOD to CBOE. (Appeals bearing postmark on or before July 20 constitute proper filing.) 
Not later than
August 5 of that year
CBOE concludes hearings and renders decisions on real and personal property appeals.
Within five business days of rendering decision  CBOE mails decisions on real and personal property appeals.  39-8-108(1) 
Within 90 days of denial Rent producing commercial real property appeals to the BAA must provide rental income, etc to CBOE within 90 days of filing appeal. 39-8-107(2)
Not later than 30 days after CBOE decision is mailed Appeals from CBOE decisions must be filed with Board of Assessment Appeals (BAA), district court, or Board of County Commissioners (BOCC) for binding arbitration.  39-8-107(2) 
Not later than 49 days after BAA decision Taxpayer appeals to court of appeals. 39-8-108(2) 24-4-106(11)(b) 
Not later than
December 15
Clerk or secretary of towns, cities, special districts, and school districts certifies levy to BOCC.  39-5-128 (1) 22-40-102(1), (3) 
Not later than
December 22
County commissioners levy taxes. 39-1-111(1)