Save Money on Colorado Property Taxes
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88%
Success Rate
$774
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4.7
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Since 2020Since 2020
Why Homeowners Choose Ownwell
Bigger Savings
Keep more of your savings with our low 35% fee. Many local firms charge more.
Colorado-Specific Expertise & Tech
Our local experts pair deep knowledge of Colorado's biennial revaluation system with advanced tech to deliver superior results.
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You risk nothing. If we don't save you money, you pay nothing.
Colorado's 2026 Property Tax Appeal Timeline
- Now
Sign up and authorize Ownwell to appeal on your behalf
We combine real-time market data, local expertise, and technology to estimate your potential savings before we file. View your savings estimate for free (no contact info required)! - By May 1, 2026
County Assessors mail Notices of Valuation (NOV)
In a non-revaluation (intervening) year like 2026, the assessor typically carries over the actual value established in the previous year unless there were physical changes to the property.
For the 2026 tax year, the valuation remains based on market data from the same July 2022 through June 2024 study period used for 2025.
- May 1 - June 8, 2026
The property tax protest window is open
This is the window to formally protest your property's assessed value with the county assessor. Ownwell files on your behalf with comparable sales evidence and a market analysis tailored to your property. - By June 30, 2026
Assessor issues Notice of Determination (NOD)
The county assessor reviews your appeal and responds with a Notice of Determination. If the value is reduced, great, you save. If not, we move to the next level.
Note, Per C.R.S. 39-5-122, in revaluation years, the assessor's NOD deadline is the last regular working day in August (Monday, Aug. 31, 2026). However, in practice, most assessors send by August 15.
Since it's a non-revaluation year, the NOD deadline is Tuesday, June 30, 2026.
- By July 15, 2026
County Board of Equalization (BOE) appeal deadline
If the assessor's determination isn't satisfactory, Ownwell files an appeal with the County Board of Equalization on your behalf. The BOE conducts a more formal hearing and issues a decision. - Within 30 days of BOE decision
Further appeal options (if needed)
The BOE must hear and conclude all appeals by Wednesday, August 5, 2026.
If the BOE decision still doesn't reflect fair value, additional appeals are available through the Board of Assessment Appeals, District Court, or Binding Arbitration.
Ownwell evaluates each case and advises on next steps.
- results
Your assessed value is lowered successfully
Your savings will be reflected in a reduced tax bill when property taxes are calculated later in the year. The lower Assessed Value means a lower tax base, and real money back in your pocket.
Is appealing always worth it? Yes.
There are only two possible outcomes of a Colorado property tax appeal:
Your assessed value is reduced, or it stays the same.
The county cannot increase your value as a result of your appeal for that tax year.
Important Colorado Property Tax Dates
2026 non-revaluation (intervening) year
NOV mailed by county assessors
By May 1, 2026
Appeal window opens
(Usually) May 1, 2026
Appeal filing deadline
June 8, 2026
Assessor issues Notice of Determination (NOD)
(Usually by) Aug. 15, 2026
BOE appeal deadline (revaluation year)
Sept. 15, 2026
Further appeals (BAA / Court / Arbitration)
Within 30 days of BOE decision
Tax bills reflect reduced value
When billed (typically late year)
*Estimated mailing notice is only an estimate and not to be used as a confirmed date
Counties We Serve in Colorado
Arapahoe
Boulder
City and County of Denver
Douglas
EL Paso
Jefferson
New counties will be launched based on demand
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Frequently Asked Questions
How do property tax appeals work in Colorado?
In Colorado, property owners can appeal their assessed value each year during the statutory appeal window (typically May 1 through June 8).
The county assessor reviews your appeal and issues a Notice of Determination (NOD). If you disagree with the NOD, you can escalate to the County Board of Equalization (BOE). Unlike some states, a property tax appeal in Colorado cannot result in your value being increased for that tax year.
Why did my property value jump so much?
Colorado revalues property statewide every two years. In revaluation years (such as 2025), values can change significantly because the assessor resets values based on recent market evidence rather than applying a small annual adjustment.
The 2026 cycle uses market data from July 2023 through June 2025. However, you can still appeal every year.
What is a Notice of Valuation (NOV)?
The NOV is the assessment notice mailed by your county assessor in revaluation years. It shows the assessor's estimate of your property's Actual Value and Assessed Value, and includes the deadline to file an appeal.
The appeal window printed on your NOV is the most important deadline to watch.
Can I still appeal in a non-revaluation year?
Yes. Even in non-revaluation years, the standard appeal window (May 1 through June 8) is available.
However, if an appeal was successful in a revaluation year, it is unlikely to result in further savings the following year since values generally carry over.
What does Ownwell do?
Ownwell specializes in property tax reduction for homeowners, small businesses, and real estate investors. We evaluate your current assessed value, perform a comparative market analysis, and prepare and file evidence on your behalf.
We attend any hearings with the county assessor or Board of Equalization to pursue a reduction. After your appeal, we continue to monitor your property's assessments and will file again if your taxes seem unfair.
What evidence is most helpful for an appeal?
The strongest evidence includes comparable sales (recent sales of similar homes nearby), documentation of condition issues (photos and contractor estimates), and any facts that make your property less marketable than typical comparable properties, such as location nuisances, needed repairs, or functional issues.
Are there fees to file an appeal?
The initial appeal with the county assessor is free, and the BOE hearing itself typically has no filing fee. Costs can apply if a case is escalated to the Board of Assessment Appeals, arbitration, or court. If Ownwell handles your appeal, we cover the required administrative steps and will confirm any costs for advanced escalation on a case-by-case basis.
What are Ownwell's fees?
There are no upfront costs. Ownwell charges a 35% contingency fee on first-year savings. If we don't reduce your property's assessed value, you pay nothing.
What is the timeline for a Colorado property tax appeal?
A Colorado property tax appeal typically moves faster than in many other states. The appeal window opens May 1 and closes around June 8.
The assessor must respond by August 15, and the BOE appeal deadline is September 15 in revaluation years.
If the matter is escalated further, additional appeals are due within 30 days of the BOE decision. Any reduction affects the tax bill calculated later that year.
Which Colorado counties does Ownwell serve?
Ownwell currently serves six Colorado counties: Arapahoe County, Boulder County, the City and County of Denver, Douglas, El Paso, and Jefferson County.