Real Property Appeals

Real Property Valuation Appeals

Real property valuation appeals will be accepted from May 1–June 3. Property owners may appeal their values using tools and information on this page or in-person. For a list of drop-in dates and times at locations throughout Boulder County during the month of May, please see the in-person appeals locations schedule.

Review Your Notice of Valuation (NOV)

Review the facts and property characteristics on your NOV for accuracy:

Appeal Form & Online Appeal

When & Where to Appeal

Comparable Property Sales for 2019/2020 Property Valuation

Provide evidence that your property value is incorrect by including comparable sales.

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Rights to Appeal

You have the right to appeal your assessed property value or its classification. State statute requires that each property in the county be re-valued by the County Assessor in odd numbered years. Property owners will receive a Notice of Value (NOV) around May 1. Please review the information regarding your property carefully. If you feel your property is valued incorrectly or there is an error in classification you may file an appeal.

Taxpayer Rights & Responsibilities

Property owners and taxpayers have specific rights, remedies, and responsibilities in the assessment process:

  • You have the right to examine the Assessor’s property records.
  • If you disagree with your property value, you may file an appeal with the Assessor.
  • You have the responsibility to provide accurate information to the Assessor about property you own.
  • You have the responsibility to participate in budget hearings held by school boards, cities and towns, and special districts that levy taxes on your property.

The Notice of Valuation

The Assessor sends a Notice of Valuation to property owners yearly that:

  • Describes the property you own
  • Gives the actual value for both the prior and current year
  • Is the form to be used in submitting an appeal to the Assessor

If your property’s value has not changed, your January tax bill is your notice of valuation for the coming year. Study your Notice of Valuation carefully. Your property value will affect your tax payment due the following year. If you believe your property’s assessed value is incorrect, you can inspect the Assessor’s records on your property and other properties.

Grounds for an Appeal

An appeal should demonstrate that your property’s estimated market value is inaccurate. For example:

  • Property Value is too high or low
  • Property Record is Incorrect

A Note Concerning Taxes

Taxes cannot be appealed through the Assessor’s office. However, some individuals may be eligible for tax relief or exemptions. The Assessor’s office can provide you with information regarding information about available property tax exemptions and/or deferrals.

Appealing a Valuation

When a property value is appealed, the Assessor reviews the value using a methodology that is similar to an appraisal. This allows the public and our appraisers to form a basis for discussion. Tools include:

Taxpayers can decide if the comparable sales indicate a reasonable value for their property, and they can identify other sales that support a request for a value adjustment.

Appeals of real property values can be filed with the Assessor between May 1 and June 3. Appeals of business personal property values can be filed with the Assessor between June 15 and July 1. Deadlines for appeal are strictly enforced.

Review Your Full-Page Notice of Valuation (NOV)

Review the facts and property characteristics on your NOV for accuracy:

Your property has been compared to similar homes that sold in the 24 month period from July 1, 2016 to June 30, 2018.

Preparing Your Appeal

Gather as much information as you can on similar properties in your area. Information on all real estate in Boulder County is available through:

Filing Your Appeal

When submitting an appeal, you must:

  • File between May 1–June 3. Post marks and submission times must be before 11:59pm June 3
  • Proof of mailing is recommended as it may be requested
  • If you file after the June 3 deadline, your right to appeal the Assessor’s decision is lost.

Note: You will not win an appeal because you think your taxes are too high. Taxes are determined by officials who determine budgets (i.e. county commissioners, city council, school boards, and special districts)

Outcome of Your Appeal

The Assessor will mail the Notice of Determination on your appeal on or before August 15.

If you disagree with the determination, you have the right to appeal to the Board of Equalization (BOE).

The deadline to appeal is September 15.

Questions about the Appeal Process

If you have any questions about the appeals process, please call 303-441-3530 to reach our Public Information staff between 8am and 4:30pm. We look forward to the opportunity to answer your questions.

The Notice of Determination is the Assessor’s response to the on-time property value appeal that you filed during the month of May. The Assessor’s deadline to mail the NOD to property owners is August 15.

In addition to showing the results of your appeal, it also gives you information you will need should you wish to appeal your determination to the Board of Equalization (BOE).

Deadline to Appeal Your Determination

If you disagree with the Assessor’s determination, you can file a written appeal to the Board of Equalization (BOE) on or before September 15.

Go to Board of Equalization (BOE)

How can I file my appeal?

You can file an appeal:

  • in person
  • mail
  • fax
  • online

When is the appeal period?

You can file an appeal from May 1 to June 3.

Where do I mail my appeal?

Boulder County Assessor
PO Box 471
Boulder, CO 80306

When will I get an answer?

A Notice of Determination will be mailed by the Assessor’s Office by August 15.

What if I disagree with my determination?

After receiving your Notice of Determination, you can file a written appeal with the County Board of Equalization by September 15. Instructions of how to file to the County Board of Equalization will be included with your notice of determination.

Contact Us


Phone: 303-441-3530
Fax: 303-441-4996

Business Personal Property
Phone: 303-441-3316
Fax: 303-441-1783

Mailing Address
Main: PO Box 471
Boulder, CO 80306-0471



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