Denver's 2026 assessor-level protest period closed June 8, 2026. The city accepted protests online through the parcel's green Protest My Value button, by signed mail, or by delivery to the Assessment Division. A timely filer should now read the Assessor's determination immediately because a further appeal goes to the Denver County Board of Equalization on the notice's deadline. An owner who did not file a 2026 protest should not reuse the closed portal or assume a late annual protest is available. Denver separately says abatement petitions may currently be filed for eligible 2024 and 2025 tax years. FairPath can organize the owner's records and evidence for an available route, but it does not revive a missed deadline, file a protest or abatement, interpret a determination, or represent the owner.
Assessment context: For tax year 2026, Denver valued real property as it physically existed on January 1, 2026. The appraisal data used to establish value came from the 24-month period ending June 30, 2024; up to five earlier years could be considered only when base-period data for a property subclass was insufficient. Residential value uses the market approach, while other property may involve market, cost, and income approaches. Review the official parcel for schedule number, actual value, land and improvements, use or classification, style, year built, living area, lot, baths, condition, and zoning. Denver's compact geography still contains sharply different condominium, historic-district, bungalow, postwar, infill, luxury, mixed-use, and industrial submarkets. Neighborhood boundary, renovation, accessory dwelling space, parking, view, traffic, and recorded physical facts can materially affect a comparison.
Filing process: During an open annual period, search the Denver Property Taxation and Assessment System, choose Real Property, open the parcel, and select Protest My Value. The city permits guest filing. A paper alternative is the current Denver Property Value Protest Form, mailed to Assessment Division - Real Property Protest, 201 W. Colfax Ave. #406, Denver, CO 80202, or delivered to the fourth floor of the Webb Municipal Office Building. The submission should identify the schedule number, explain the alleged value or classification error, give an owner value position, and attach support. Save the online receipt or signed form and delivery proof. After review, an appraiser either adjusts the value or classification or denies the protest. A dissatisfied timely filer then follows the determination's County Board instructions; later state Board, district-court, or binding-arbitration options arise only after the county stage.
Evidence to review: Anchor every exhibit to Denver's 2026 appraisal date and data period. For residential property, choose verified sales from the period ending June 30, 2024 that match the subject's neighborhood, design, living area, lot, effective age, quality, condition, parking, and renovation status. Later sales may describe a current market but do not prove the historical value under Denver's stated 2026 model period. Use the city parcel record to identify incorrect square footage, condition, bath count, use, or classification because Denver expressly lists those as protest grounds. Dated interior and exterior photographs, permits, inspections, contractor scopes, structural reports, leases, or income statements should connect a claimed difference to January 1, 2026. A concise adjustment table is stronger than an unfiltered list of lower-priced sales, especially where Denver neighborhood boundaries or historic character create distinct submarkets.
Current deadline guidance: 2026 assessor protest window closed June 8, 2026. Denver accepted 2026 real-property valuation protests from May 1 through June 8, 2026. That assessor-level window is closed. Owners who timely protested must follow the deadline in the Assessor's determination for any County Board of Equalization appeal. Separate abatement petitions are currently available for eligible 2024 and 2025 tax-year claims.
Denver's 2026 annual protest window ran May 1 through June 8 and is now closed; a County Board deadline comes from the determination issued after a timely protest.
Denver's official online workflow starts in the parcel record and uses the green Protest My Value button; the city also accepted mail and in-person forms during the window.
The 2026 value reflects property as it existed January 1, 2026 but uses appraisal data from the 24 months ending June 30, 2024, with limited earlier data only for thin subclasses.
Denver currently identifies 2024 and 2025 as potential abatement years and states that the 2024 petition must be filed no later than January 2, 2027.
Official filing authority: City and County of Denver Assessment Division. https://www.denvergov.org/Government/Agencies-Departments-Offices/Agencies-Departments-Offices-Directory/Department-of-Finance/Our-Divisions/Assessors-Office/Protest-Property-Values
Source: City and County of Denver Assessment Division, Protest Property Values for the 2026 Tax Year, https://www.denvergov.org/Government/Agencies-Departments-Offices/Agencies-Departments-Offices-Directory/Department-of-Finance/Our-Divisions/Assessors-Office/Protest-Property-Values. Reviewed 2026-07-16.
Source: City and County of Denver, Assessor Frequently Asked Questions, https://denvergov.org/Government/Agencies-Departments-Offices/Agencies-Departments-Offices-Directory/Department-of-Finance/Our-Divisions/Assessors-Office/Assessment-FAQ. Reviewed 2026-07-16.
Source: City and County of Denver, Denver Property Taxation and Assessment System, https://www.denvergov.org/property. Reviewed 2026-07-16.
Source: Colorado Judicial Branch, Colorado Property Tax Appeal Self-Help, https://www.coloradojudicial.gov/self-help/property-tax-appeal. Reviewed 2026-07-16.