Castle Rock, Colorado sales tax rate: 8.1%
Last updated Checked monthly
The sales tax rate in Castle Rock, Colorado is 8.1%. That’s the 2.9% state rate plus 5.2% in local taxes. It’s higher than 69 of the 114 Colorado cities we checked.
Calculated by the 
Sales Tax APIThe same engine Zamp customers use.Castle Rock combined rate
8.1%
- Colorado state
- 2.9%
- Douglas CountyCounty
- 1%
- Castle RockCity
- 4.2%
Castle Rock sales tax calculator
Enter a price and what you’re selling.
- ColoradoState · 2.9%$2.90
- Douglas CountyCounty · 1%$1.00
- Castle Rock TownCity · 4.2%$4.20
Charging this at checkout? Zamp calculates it on every order and files the returns.
Book a demoCastle Rock sales tax rate breakdown
State, county and city taxes add up to 8.1%.
| Jurisdiction | Type | Rate |
|---|---|---|
| State of Colorado | State | 2.9% |
| Douglas County | County | 1% |
| Castle Rock Town | City | 4.2% |
| Combined rate | 8.1% |
Rate history
- July 20233.9%
- July 20247.9%
- July 20258.1%
- July 20268.1%
- Today8.1%
Changed since July 2023.
Sales tax near Castle Rock
Closest cities
- Lone Tree11 mi7.5%
- Centennial15 mi6.75%
- Foxfield15 mi8%
- Greenwood Village17 mi7.25%
- Palmer Lake18 mi7.13%
- Englewood20 mi8.05%
- Kiowa21 mi5.4%
- Aurora24 mi8%
Elsewhere in Douglas County
- Lone Tree7.5%
Charge the right rate in Castle Rock, on every order.
Zamp calculates tax at each customer’s address, then files and pays every Colorado return for you, with a sales tax team you can call.
Castle Rock sales tax questions.
Still have questions? Call us at 1-866-438-9267 or email us at support@zamp.com.
What is the sales tax rate in Castle Rock, Colorado?
The combined sales tax rate in Castle Rock is 8.1% as of November 2, 2026. It’s made up of 2.9% Colorado state tax, 1% Douglas County, 4.2% Castle Rock Town.
Does the sales tax rate vary within Castle Rock?
Castle Rock has no special-district taxes, so most addresses in the city pay the same 8.1%: Colorado’s 2.9% plus 1% county tax plus 4.2% city tax. This rate was calculated for Castle Rock’s 80104 ZIP code; the calculator prices any exact address.
Is SaaS taxable in Castle Rock?
Partly. Colorado taxes 33% of the price of software as a service, so the effective rate in Castle Rock is 4.2%.
Do online sellers have to collect sales tax in Castle Rock?
Yes, if they have nexus in Colorado: more than $100,000 in Colorado sales in the previous or current calendar year, or a physical presence in the state. They register with the Colorado Department of Revenue and charge the rate at the buyer’s address.
Sources. Colorado Department of Revenue · Zamp Sales Tax API, for Castle Rock’s 80104 ZIP code. Rates are checked monthly and are for information, not tax advice.
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