Colorado Property Tax Appeal Guide
How to challenge your property tax assessment in Colorado - deadlines, process, and a savings calculator.
What This Data Tells Us About Appeals in Colorado
- Administrative filing in Colorado is listed at $0, so the first barrier is evidence and timing, not a petition fee.
- This ACS extract does not store how often Colorado assessments are reduced on appeal; comparable sales and property-record errors are the evidence the named board typically asks for.
- The typical window centers on June; confirm the current county notice date before relying on the statewide summary. Compare Idaho's June window before assuming Colorado is early or late.
Primary signal
The administrative filing is usually free
File with the County Board of Equalization. The reported filing-fee structure is $0; later court or tribunal stages may use a different schedule.
Decision signal 2
Colorado's process has its own procedural details
Colorado reassesses every two years (odd years). If you miss the protest deadline, you cannot appeal until the next reassessment cycle.
Decision signal 3
This extract does not store an appeal-win rate
The ACS county medians on this site do not include how often Colorado assessments are reduced on appeal. Recent comparable sales and documented property-record errors are the evidence boards typically ask for.
Decision signal 4
The filing window centers on June
June 1 deadline for protests (odd-numbered reassessment years). Deadlines can vary by county and assessment cycle, so confirm the current date with the local assessor before relying on this guide.
How to read this guide and disclaimer
Use the ranked signals above as a preparation order, not as a forecast. Start with the filing window and named appeal body because a strong valuation argument cannot cure a missed deadline or a filing sent to the wrong office. Then compare the assessment with recent, genuinely similar properties and document factual errors such as incorrect square footage, condition, or classification.
An estimated success rate is not part of this ACS extract. Keep copies of the assessment notice, evidence, forms, delivery confirmation, and every response from the taxing authority. If a state rule and a county instruction differ, follow the current instruction issued by the office that will hear the appeal.
This guide is for informational purposes only and is not legal or tax advice. Deadlines, filing fees, and procedures vary by county within Colorado and can change year to year. Always verify the current rules with your local assessor's office, or a licensed attorney or tax professional, before filing. Source: Colorado Division of Property Taxation.
Appeal calendars beside Colorado
Other state boards, not geography. Use them to see whether Colorado's June window is unusual; start with Idaho and Indiana.
| Peer state | Typical month | Filing fee |
|---|---|---|
| Idaho Also open Idaho appeal steps | June | $0 |
| Indiana Also open Indiana appeal steps | June | $0 |
| Montana Also open Montana appeal steps | June | $0 |
| Nebraska Also open Nebraska appeal steps | June | $0 |
| North Carolina Also open North Carolina appeal steps | June | $0 |
Appeal Deadline
June 1 deadline for protests (odd-numbered reassessment years)
Appeal Body: County Board of Equalization
Step-by-Step Appeal Process
- 1
Review your Notice of Valuation received in May (reassessment years)
- 2
File a protest with the County Assessor by June 1
- 3
Attend an informal conference or submit evidence in writing
- 4
If unresolved, appeal to the County Board of Equalization by July 15
- 5
Further appeals go to the Board of Assessment Appeals or District Court
Colorado-Specific Notes
Colorado reassesses every two years (odd years). If you miss the protest deadline, you cannot appeal until the next reassessment cycle.
Source: Colorado Division of Property Taxation
Estimate appeal savings
After you have Colorado's deadline (June) and filing route (County Board of Equalization), project annual savings if an assessment cut sticks. The shared estimator lives on one tools URL so each state page keeps its own process facts instead of reprinting the same form.
Open appeal savings estimator →