Commissioners: “We will continue to value, respect, and support all individuals as we serve the people of Boulder County.” Read full message.

Immigrant Resources, including a Know Your Rights Booklet, available on the Immigration Resources webpage.

Assessor’s Office
Boulder Valley farmland landscape, with mountains to the right

Assessors Office

News and Information

Business Personal Property

Owners of taxable Business Personal Property in Boulder County as of January 1 are required to file a Business Personal Property Declaration every year.
The 2025 deadline to timely file a Business Personal Property Declaration is April 15.
File a Business Personal Property Declaration

Real Property

Real Property Value Appeals will be accepted May 1 through June 9, 2025

Senior Exemption Applications

Please visit the Senior Exemptions page to learn more.

Qualifying Veteran with a Disability Exemption and Gold Star Spouse Applications

Please visit the Veteran Related Exemptions web page to learn more.

Assessor Overview

The Assessor’s Office establishes values every two years for more than 120,000 properties within Boulder County, worth more than $120 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

Services and Information

Contact Us

Assessor

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

Email

Mailing Address

PO Box 471
Boulder, CO 80306-0471

Hours: 7:30 a.m. to 5 p.m.
Monday-Thursday
Closed Friday

Locations

Assessor Boulder and Longmont Drop Boxes

Boulder

1325 Pearl St., 2nd floor
Boulder, CO 80302
Hours: 7:30 a.m. to 5 p.m.
Monday-Thursday
Map and Directions Boulder Location

Longmont

515 Coffman St., Suite 114
Hours: 7:30 a.m. to 5 p.m.
Monday only
Map and Directions Longmont Location

Lafayette

1755 S Public Road
Hours: 7:30 a.m. to 5 p.m.
Tuesday only
Map and Directions Lafayette Location