Boulder County, Colorado · Boulder
Boulder County property tax appeal guide
Protest to the assessor in early June. Boulder values run high, so comparable-sales evidence matters. You appeal through the Boulder County Assessor; Colorado uses Real Property Notice of Valuation protest (county form) filed with the County Board of Equalization (CBOE).
Boulder County appeal deadline
Protest to the assessor in early June (the date is printed on your Notice of Valuation).
County assessors mail Notices of Value by May 1. The protest deadline is in early June and the exact date is printed on your notice — recent law has shifted it for some counties, so always use the date on your NOV rather than assuming June 1.
How to appeal in Boulder County
1. Notice of Valuation (by May 1)
Your county assessor mails a Notice of Valuation by May 1 showing 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.
2. Protest to the assessor (early June)
File a written protest with the assessor by the deadline printed on your NOV — typically the first week of June. Include 3-5 comparable sales from the state's defined data-gathering period. No filing fee.
3. Assessor's determination (Notice of Determination)
The assessor reviews your protest and mails a Notice of Determination, usually by late June. If you disagree, you may appeal to the County Board of Equalization (CBOE).
4. County Board of Equalization hearing
The CBOE hears appeals, generally in July. Present your comparable-sales evidence to a referee or the board. Confirm your hearing date with the county.
5. Further appeal (optional)
If the CBOE denies your appeal, you generally have 30 days to escalate to the Board of Assessment Appeals (BAA), binding arbitration, or district court.
Boulder County property tax FAQ
What is the property tax appeal deadline in Boulder County, Colorado?
Protest to the assessor in early June (the date is printed on your Notice of Valuation). County assessors mail Notices of Value by May 1. The protest deadline is in early June and the exact date is printed on your notice — recent law has shifted it for some counties, so always use the date on your NOV rather than assuming June 1.
What form do I use to appeal in Boulder County?
Colorado uses Real Property Notice of Valuation protest (county form), filed with the County Board of Equalization (CBOE). There is no filing fee to appeal.
When is the Colorado property tax protest deadline?
Early June — the exact date is printed on your Notice of Valuation, which assessors mail by May 1. Recent law has shifted the date for some counties, so rely on your notice rather than assuming June 1.
Other Colorado counties
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