How to Appeal Property Taxes in Denver County, Colorado (2026 Guide)

For Denver’s 2026 tax year, the residential property-value protest window ran May 1, 2026 through June 8, 2026; the protest had to be received or postmarked by June 8, 2026. File online through Denver’s Property Taxation and Assessment System, or use the 2026 Property Value Protest Form and mail/drop it at the Assessment Division, 201 W. Colfax Ave., Dept./#406, Denver, CO 80202. Denver does not list a fee for the county-level protest.

How assessments work in Denver County

Denver property taxes start with the actual value set by the City and County of Denver Assessment Division. For the 2026 property value assessment, Denver says your property is valued as it existed on January 1, 2026, but the sales data used to set value comes from the 24-month base period ending June 30, 2024—generally July 1, 2022 through June 30, 2024. Residential property is valued using the market approach, meaning sales of similar homes; other property types may use market, cost, and income approaches.

Colorado reappraises real property every two years, in odd-numbered years. Denver’s 2026 value is therefore tied to the 2025/2026 level of value, not to what your home might sell for in mid- or late-2026. That matters: a lower sale in 2026 is useful background, but the strongest protest evidence usually shows what the home was worth as of June 30, 2024, with the home’s physical condition as of January 1, 2026.

Denver’s 2025 taxes payable in 2026 used two residential assessment-rate/mill-levy pieces: local government at 6.25% and 27.328 mills, and schools at 7.05% and 52.274 mills. Denver’s published combined example for a $625,000 typical single-family home produces about $3,370.82 in tax before any special facts or exemptions.

Whether you should appeal

Appeal if you can point to a concrete error or better market evidence—not just “my tax is too high.” Denver specifically lists these reasons: wrong square footage, condition, bath count, use/classification, or an estimated value that is too high.

Start with Denver’s Property Search. Pull your property record and compare the listed living area, finished basement, year built, quality/condition, unit count, garage, lot, and property class. Then use Denver’s “Compare Properties” tool to find sales in your immediate area during the base period. Best comps are similar in location, style, size, condition, and sale date; avoid relying on a renovated Congress Park bungalow to contest an unrenovated Athmar Park ranch.

Denver does not appear to publish a current countywide homeowner protest success rate or median reduction. Do not assume filing alone gets a reduction. A strong Denver protest usually says: “The Assessor used $X; I estimate $Y because these three base-period sales are more comparable, and the record overstates my finished square footage by Z.”

A realistic savings example: suppose Denver values your home at $700,000, but three base-period comps support $650,000. A $50,000 reduction would save roughly $269.67 for taxes using Denver’s 2025-payable-2026 residential rates: $50,000 × [(6.25% × 27.328 mills) + (7.05% × 52.274 mills)]. The exact savings can differ if your parcel has special districts, exemptions, or later mill-levy changes.

Step-by-step how to file

1. Find your parcel. Go to Denver’s Property Taxation and Assessment System and search by address, Parcel ID, or schedule number. Open the real property record.

2. File online if possible. Denver’s instructions say to click the green “Protest My Value” button under Assessment Details. You may sign in as a guest. The online protest window was May 1–June 8, 2026.

3. Or use the paper form. The official paper form is the “2026 Property Value Protest Form”; the PDF itself is titled “Optional 2026 Protest Form.” It asks for parcel number, owner, property address, your estimate of value as of June 30, 2024, your reason, supporting documents, signature, phone, and email.

4. Attach evidence. Include comparable sales, photos of condition problems, contractor estimates, inspection reports, or an appraisal if it addresses the correct valuation date. For factual errors, mark up the property record and attach photos or measurements.

5. Submit by an accepted method.

   • Portal: Denver Property Taxation and Assessment System, via the “Protest My Value” tab.
   • Mail: Department of Finance, Assessment Division – Real Property Protest, 201 W. Colfax Ave. #406, Denver, CO 80202.
   • In person/drop-off: Assessment Division, 4th floor, Wellington E. Webb Municipal Office Building, 201 W. Colfax Ave., Denver, CO 80202.
   • Email: Denver’s current-year real property protest page does not list email as a filing method. Do not rely on email unless the Assessor’s Office confirms it in writing. Denver lists bocc.protest@denvergov.org for Board of County Commissioners abatement petitions for prior years, not for the normal current-year real property protest.

There is no county protest filing fee listed by Denver. Keep a copy of everything and proof of mailing/postmark or online confirmation.

What happens after

At the first level, this is usually a document review, not a courtroom hearing. Denver says a submitted protest is assigned to an Assessor’s Office appraiser, who reviews your evidence and either adjusts the value/classification or denies the protest and keeps the current value. Denver’s protest line is 720-913-4164.

If you disagree with the Assessor’s determination, the next local authority is the Denver County Board of Equalization. Denver’s charter creates a Board of Equalization made up of designated city officers or their designees; it performs the equalization, reduction, abatement, and rebate functions that county commissioners perform elsewhere in Colorado. Watch the determination letter closely because it should tell you the next appeal deadline and where to file.

After the county board level, Colorado gives three routes: appeal to the Colorado Board of Assessment Appeals, file in district court, or choose binding arbitration. The Colorado Judicial Branch says you generally must first protest to the Assessor, then appeal to the County Board of Equalization, and then start the next appeal no later than 30 days after the county board decision is mailed. District court filing is listed at $235; BAA fees are different—taxpayers without an attorney pay no fee for the first two petitions, then $33.75 for later petitions, while attorneys/agents pay $101.25 per petition.

BAA hearings are currently by Zoom. The petitioner presents first; the county usually has an attorney and an appraiser. BAA evidence is not automatically imported from Denver, so resubmit your exhibits under BAA Rule 11 deadlines.

Local tips

• Use the right time window. For Denver 2026, base-period sales ending June 30, 2024 are the core evidence. Later sales may be less persuasive unless used carefully to explain condition or market context.
• Do not forget exemptions. Colorado’s senior/veteran “homestead” style exemption can exempt 50% of the first $200,000 of actual value for qualifying seniors, veterans with a disability, and qualifying surviving spouses. For 2026, senior applicants generally must have been born on or before January 1, 1961 and owned/occupied the home since January 1, 2016. Denver also has a local Property Tax Relief Program for qualifying homeowners and renters; 2025 rebate applications run May 1, 2026 through April 30, 2027, subject to funding.
• Correct facts even if value looks close. An overstated finished basement or bath count can follow you into future years.
• Prior years are different. Denver’s abatement/refund process is for the immediate two prior years; in 2026, Denver’s forms page says tax years 2024 and 2025 are open. That is a separate petition, not the normal 2026 protest.