Colorado Property Tax Appeal Guide
Colorado values residential property at actual (market) value, then applies a low residential assessment rate (about 6.7%) set by statute to derive taxable value.
7%
Statutory percentage
June 1 (odd years — reassessment years)
Verified July 2026 — confirm on your notice
Colo. Rev. Stat. § 39-5-122 (protests and appeals)
Governing state code
How to File in Colorado
Review the Notice of Valuation mailed by the county assessor on or before May 1.
File a protest with the county assessor by June 8 (in person, by mail, or online).
Provide comparable sales from the applicable prior data-gathering period.
If denied, appeal to the County Board of Equalization by July 15.
Further appeal to the Board of Assessment Appeals, district court, or arbitration.
Deadlines and ratios vary by county and change over time — always confirm with your local assessor. This is general information, not legal advice.
Are you actually over-assessed in Colorado?
Check this property against recent comparable sales for $4.99. If the evidence says you have no case, you know that before you spend a filing deadline on it — and if it does, the same $4.99 is credited toward the full appeal packet.
A worked example in Colorado
Say the assessor values your home at $400,000, but comparable sales show it is really worth $350,000 — a $50,000 over-assessment. Colorado taxes 7% of value, so the taxable amount drops from $26,800 to $23,450. At a typical effective rate of ~1.5%, that is about $50 back in your pocket every year until the value is corrected.
Illustration only. Your actual rate, exemptions, and savings depend on your county and taxing districts — run your own numbers.
Common grounds for a Colorado appeal
Over-market valuation. Comparable sales of similar nearby homes closed below the value the assessor placed on yours.
Errors in the property record. The county has the wrong square footage, bedroom or bathroom count, lot size, or condition on file.
Unequal (non-uniform) assessment. Comparable properties in your area are assessed for less than yours, regardless of market value.
Physical or external problems. Deferred maintenance, functional issues, or an external nuisance depress what a buyer would pay.
Overvaluation · Incorrect classification · Unequal assessment · Denial of exemption
Don’t overlook exemptions
An appeal lowers your value, but exemptions cut your taxable base directly — and both stack. Most owners qualify for a homestead exemption on their primary residence, and many states add relief for owners over 65, veterans, and people with disabilities. Confirm you are enrolled with your Colorado county assessor before filing — it is the fastest saving most people miss.
- Senior/Disabled Veteran Exemption 50% of first $200,000 of actual value
- Age 65+ (10 years), long-term ownership
- Disabled Veteran Exemption 50% of first $200,000
- 100% service-connected disability
Who hears a Colorado appeal
Your appeal is decided by County Assessor / Board of Equalization — the value itself is set by the County Assessor, which is who you are disagreeing with.
- 1
Assessor protest
- 2
County Board of Equalization
- 3
Board of Assessment Appeals
- 4
Court of Appeals
Each stage has its own deadline. Missing the first one usually closes the later ones for that tax year.
Key Colorado statutes
The sections a Colorado appeal is argued under. Quote one exactly as written — a paraphrased or renumbered citation is worse than none.
- C.R.S. §39-1-103
- Actual Value Defined
- C.R.S. §39-1-104
- Assessment Rate
- C.R.S. §39-5-121
- Notice of Valuation
- C.R.S. §39-5-122
- Protest to Assessor
- C.R.S. §39-8-106
- Appeal to CBOE
- C.R.S. §39-8-108
- Appeal to BAA
Official Colorado resources
These are state government sites. The form and portal you actually file through are published by your county assessor.
Colorado property tax appeal questions
- When is the deadline to appeal property taxes in Colorado?
- June 1 (odd years — reassessment years). Verified July 2026. Deadlines vary by county and change from year to year, so always confirm the date printed on your own assessment notice before you file.
- Who decides a property tax appeal in Colorado?
- County Assessor / Board of Equalization hears it. The full path is: Assessor protest, then County Board of Equalization, then Board of Assessment Appeals, then Court of Appeals.
- What is the assessment ratio in Colorado?
- 6.25% of actual value for local government levies; 7.05% for school district levies (residential, 2025–2026; subject to annual legislative adjustment). That is the share of value your bill is calculated on, so lowering the assessed value lowers the bill proportionally.
- What grounds can I appeal on in Colorado?
- Colorado recognises these grounds: Overvaluation, Incorrect classification, Unequal assessment, Denial of exemption. Overvaluation is the most common — you show comparable sales that closed below your assessed value.
- What property tax exemptions does Colorado offer?
- Senior/Disabled Veteran Exemption — 50% of first $200,000 of actual value, for age 65+ (10 years), long-term ownership; Disabled Veteran Exemption — 50% of first $200,000, for 100% service-connected disability. Exemptions reduce your taxable base directly and stack with an appeal, so check both.
- What is the average property tax rate in Colorado?
- About 0.5% of market value per year statewide. Your own rate depends on your county and its taxing districts, so treat this as a benchmark rather than your bill.
Colorado Tax Estimator
$0 / yr
Based on 7% ratio & avg. millage. Estimate only.
Generate your Colorado appeal packet
Check your property for $4.99 (credited), then get the full comparable-sales packet and AI appeal letter for a flat $29 — $19 at launch.