Assessment Ratio
6.55%
Protest Deadline
June 1, 2026
Official Form
Real Property Appeal
Risk of Increase
No
How Assessment Works in Colorado
Colorado assesses residential property at 6.55% of actual (market) value. Commercial property is assessed at 29%. Your tax bill is based on the assessed value (6.55% of market value), not the full market value. The residential rate is set by the legislature and can change.
How to File in Colorado
File with your county assessor by mail, in person, or online (where available). The deadline is June 1 for the current reassessment year.
Step-by-Step
Colorado Protest Process
Receive your Notice of Valuation from the county assessor (mailed by May 1 in reassessment years).
File a protest with the county assessor by June 1.
The assessor reviews your evidence and issues a Notice of Determination.
If not satisfied, appeal to the county Board of Equalization within 30 days.
If still unresolved, appeal to the Board of Assessment Appeals (BAA) or district court.
FAQ
Colorado Property Tax Protest Questions
Can my Colorado assessment increase during a protest?
No. Colorado law prohibits the assessor from increasing your value during the protest process. Your value can only stay the same or go down.
How does the 6.55% ratio work?
If your home has a market value of $500,000, the assessed value is $32,750 (6.55%). Your tax bill is this assessed value multiplied by your mill levy. If the county overvalues your home at $550,000, you pay taxes on $36,025 instead of $32,750.
How often does Colorado reassess properties?
Colorado reassesses all property every two years (biennial cycle). The most recent reassessment used a June 30, 2024 valuation date. You can only protest in the reassessment year or if there's a change in your property.
What is the effective property tax rate in Colorado?
Colorado property tax rates vary by county, municipality, and school district, but the effective rate (annual tax paid divided by market value) typically ranges from about 0.5% to 2.5%. Because Colorado assesses property at 6.55% of market value, your actual tax bill depends on both the assessed value and the local millage or mill levy applied on top of it. If your assessed value is higher than comparable sales support, filing a protest is one of the only ways to reduce your effective rate without waiting for a reassessment.
How long does a property tax protest take in Colorado?
Most Colorado protests take between 6 weeks and 6 months from filing to final decision. After you file Real Property Appeal, the assessor or review board schedules a hearing — typically within 30 to 90 days — and issues a written decision shortly after. Cases that settle informally resolve faster, while cases that advance to a formal hearing or court appeal can take several additional months. ProtestMax prepares your full evidence packet in minutes so you can file immediately and start the clock.
Can I protest my property taxes every year in Colorado?
Yes. In Colorado, homeowners generally have the right to protest their property tax assessment every year, as long as you file by the June 1, 2026 deadline. Even if you won a reduction last year, your assessor can revalue your property the following year, and you retain the right to challenge the new value. Annual protests are especially important during years when market values are flat or falling but assessments keep rising.
What evidence is most persuasive in Colorado hearings?
The strongest evidence in a Colorado protest hearing is recent comparable sales — homes similar to yours in size, age, condition, and location that sold for less than your assessed value within the last 6 to 12 months. Equity comparisons (similar homes assessed for less than yours) are also highly persuasive. Photos of deferred maintenance, structural issues, or negative location factors (busy roads, flood zones, power lines) strengthen your case further. ProtestMax assembles all of this evidence into a hearing-ready packet tailored to Colorado's rules.