Colorado property tax answers · Updated June 2026
How do I protest my property taxes in Colorado?
The short answer
Your county assessor mails a Notice of Valuation by May 1. You protest in writing to the assessor by the deadline printed on that notice, typically the first week of June. There is no fee. Include 3 to 5 comparable sales from the state's defined data-gathering period. If the assessor denies you, appeal to the County Board of Equalization, and beyond that to the Board of Assessment Appeals, arbitration, or district court. Colorado reassesses in odd-numbered years.
The Colorado protest, step by step
- Watch for your Notice of Valuation (NOV), which your county assessor mails by May 1. It shows your new actual value. Colorado reassesses in odd-numbered years (the last was 2025); in even years values usually carry forward, but you can still protest.
- Protest in writing to the assessor by the deadline printed on your NOV, typically the first week of June. Recent law has shifted the date for some counties, so use the date on your notice rather than assuming June 1. There is no filing fee.
- Include 3 to 5 comparable sales drawn from the state's defined data-gathering period. Colorado is a disclosure state, so usable sales comparables are the backbone of a protest here.
- Read the assessor's Notice of Determination, usually mailed by late June. If you disagree, appeal to the County Board of Equalization (CBOE), which generally hears cases in July.
- If the CBOE denies you, you generally have 30 days to escalate to the Board of Assessment Appeals (BAA), binding arbitration, or district court.
Why the sales-comp argument is strong in Colorado
Unlike Texas, Colorado is a full-disclosure state, so sale prices are usable evidence. The catch is WHICH sales: Colorado only considers sales inside a fixed statutory data period, the two years ending June 30 of the year before the January 1 assessment date, so the most recent sales are frequently outside it and the county cannot consider them. That makes a comparable-sales table drawn from inside that window, similar homes that sold for less than your valuation, the most direct way to a reduction. Boulder and the Denver metro counties have seen sharp, uneven appreciation, which is precisely where comparable gaps open up. Your county's data and an address check are on our Colorado page.
One timing note: because reassessment happens in odd years, the value set in 2025 generally governs 2026 too, so a reduction you win can carry across the cycle. Protesting is free at the assessor and CBOE stages, so the only cost is the evidence and your time.
Get the comps, skip the contingency
Colorado's assessor and CBOE stages are built for homeowners, so an attorney is rarely necessary for a standard home. The free check shows how your valuation compares to similar properties in about 30 seconds, no signup. If the record shows a case, the $49 Property Assessment Audit comes with the comparable evidence pre-filled, ready to sign and submit, and you keep 100% of the savings with no percentage cut.
See if your home is over-assessed, free
Search your address and see how your assessment compares against similar properties from the public assessment roll. Free, no signup, about 30 seconds. If the record shows a gap, the $49 Property Assessment Audit comes pre-filled with your comparable evidence and the filing steps for your jurisdiction, you sign and submit, and you keep 100% of the savings. No contingency, ever.
Check my address · FreeFlat $49, one time. Filing your own appeal is free in every state; what you're buying is the evidence and the steps, done.