For 2026, the sales tax rate in Boulder County, Colorado stands at 8.845% — a combination of the 2.9% state rate and 5.945% local levy. The county's 330,758 residents make it an important market in the region.
For a $500 purchase in Boulder County, the sales tax would be $44.23, bringing the total to $544.23.
Business Compliance in Boulder County
Businesses must register with the Colorado Department of Revenue to collect and remit sales tax. Filing frequency depends on sales volume. With a population of 330,758, Boulder County offers significant market potential for businesses of all sizes.