Assessor's Office

News & Information

Assessor’s Office Status

All Assessor’s Office locations (the main location in Boulder as well as remote offices in Longmont and Lafayette) are closed to walk-in traffic until further notice.

Staff are available online and by phone during regular business hours to take your questions or schedule appointments. Please call 303-441-3530, or email Assessor@BoulderCounty.org.

Valuation Appeals—Notice of Determination

The Assessor’s deadline to mail determinations of property value appeals is September 16. If you disagree with the Assessor’s determination, you can file a written appeal to the Board of Equalization (BOE) on or before September 28.

• About your Notice of Determination
• Assessment Calendar

Overview

The Assessor’s Office establishes values every two years for more than 120,000 properties within Boulder County, worth nearly $50 billion in market value, using tools such as geographic information systems (GIS) and mass appraisal techniques to perform the appraisal analysis. Property values are used to set tax amounts which the Treasurer’s Office administers and collects.

Connect With Us

• Assessor/Treasurer Change of Address form.
• View the Assessor A-Z guide.
• Schedule a meeting with Assessor staff.
• Ask a question about your Business Personal Property. Appeals are accepted June 15–30 each year.
• Ask a question about your Real Property. Appeals are accepted May 1–June 1 each year.
• Ask a question about your Senior Exemption. Applications must be filed by July 15.
• Search for your Notice of Value (NOV) online.
• 2020 Assessor’s Office State of the County video.