Assessor's Office

News & Information

Notices of Valuation to be mailed May 1

The Boulder County Assessor’s Office has completed its biennial reappraisal of all property in Boulder County. Notices of valuation are mailed to property owners on Saturday, May 1. For details and information, see: 2021 Reappraisal Announcement

These maps display:

• 24-Month Median Value Increases for 2021 Reappraisal of Single Family Residences
• 2021 Boulder County Residential Values

Property Value Appeals are accepted May 1 through June 1, 2021

Appeal Your Property Value

Business Personal Property

• Business Personal Property Overview
• About Business Personal Property Declarations
• File Online for Business Owners Online filing will open February 1, 2021. (Available to businesses who received a postcard in lieu of a full declaration.) Deadline for filing declarations: April 15.

Assessor’s Office New Hours

The Assessor’s Office is one of several Boulder County departments participating in a pilot program to explore moving to a four-day work-week.

Starting January 4, the Assessor’s Office staff will be available Monday through Thursday, 7:30 a.m.–5:00 p.m. online and by phone, to take your questions or schedule appointments. Please call 720-574-1880, or email Assessor@BoulderCounty.org.

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.

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 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.