Is your Colorado home
valued too high for taxes?
Colorado's biennial reassessment cycle means errors sit on your bill for two years before the next chance to correct them. The June 1 protest deadline arrives fast.
Average Colorado homeowner overpayment when overassessed: $892/year — across 2 tax years, that's $1,784 lost.
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Colorado Notice of Valuation — June 1 Deadline
Colorado sends Notices of Valuation in odd-numbered years. Property owners must file an informal protest with their county assessor by June 1 (or within 30 days of mailing). Unresolved protests escalate to the County Board of Equalization (CBOE), then to the State Board of Assessment Appeals (BAA). Missing June 1 means you cannot appeal until the next 2-year cycle.
All 64 Colorado Counties
Select your county to see your local tax rate, average overpayment, and filing options.
Why Colorado Homeowners Are Getting Overcharged
Colorado assesses residential property at 6.95% of actual value (the residential assessment rate). Your tax bill equals: actual value × 6.95% × mill levy. Every dollar of overvaluation directly inflates your bill — at 6.95% on the assessed portion.
Colorado's biennial reassessment cycle means valuations are based on 18-month sales windows ending June 30 of the prior year. In a market that rose sharply in 2021–2022 and has since corrected, many counties locked in peak-market assessments that now exceed current values. The next reassessment cycle doesn't correct this automatically.
Front Range counties — Denver, Arapahoe, Jefferson, Douglas, Adams, Boulder — saw the sharpest appreciation and now carry the highest appeal potential. Resort counties like Eagle (Vail), Summit, and Pitkin also frequently see assessor errors due to high-value, low-comparable-sales markets.
Assessment cannot go up from a Colorado appeal
Colorado protest proceedings can only reduce or confirm your assessment — never increase it. Your appeal cannot raise your tax bill. There is zero risk to checking and filing.
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How Colorado Property Tax Protests Work
- 1
Receive your Notice of Valuation in odd-numbered years
Colorado sends Notices of Valuation in odd-numbered years (2025, 2027, etc.). The notice shows your assessor's estimated actual value. Compare it to recent comparable sales — if it's higher than what similar homes are actually selling for, you have grounds to protest.
- 2
File an informal protest with your county assessor by June 1
File ABCDE-1 or your county's equivalent protest form with the county assessor by June 1 (or within 30 days of the Notice of Valuation). The assessor must respond by June 30. Fairmark prepares and files all protest documentation.
- 3
Escalate to the County Board of Equalization if needed
If the informal protest doesn't resolve the dispute, you can escalate to the County Board of Equalization (CBOE). CBOE hearings are informal and evidence-based. From CBOE, adverse decisions can be appealed to the State Board of Assessment Appeals (BAA).
- 4
Receive your corrected 2-year valuation
A successful Colorado protest reduces your actual value for the current 2-year assessment cycle. Both years of the cycle benefit from the lower valuation — doubling the effective savings of a single appeal.
Your Colorado county is counting on you not checking.
Type your address. See if your 2-year valuation is inflated. Takes 10 seconds. Free.
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