Sales Tax in Thornton, Colorado in 2025

We'll walk you through how the sales tax rate is determined for Thornton and address some common questions you may have. We'll also cover how to collect, audit, and remit sales tax in Thornton.

Plus, we’ll share the best solution that will ensure you are always compliant across the entire sales tax lifecycle.

Disclaimer: Our sales tax data is updated on a quarterly basis.

Thornton Sales Tax Rate 2025

Thornton is located in Colorado, United States. Its minimum sales tax rate is 4.75%, and its maximum sales tax rate is 6.65%. These rates include local and state sales tax rates.

Here is how the Thornton sales tax rates breaks down:

Tax Jurisdiction	Min. Rate	Max. Rate
State Tax	2.90%	2.90%
County Tax	0.00%	0.75%
City Tax	3.75%	3.75%
Special Tax	0.00%	1.10%
Combined Rate	4.75%	6.65%

County Sales Tax in Thornton

Thornton overlaps with 2 counties in Colorado. Below, you can see the county sales tax rates for each one:

County	Sales Tax Rate
Weld County	0.00%
Adams County	0.75%

Sales Tax Rates in Thornton by Zip Codes and Districts

Below are the sales tax rates in Thornton broken down by districts and zip codes:

District	Zip Codes	Combined Sales Tax Rate
ADAMS COUNTY|SCIENTIFIC AND CULTURAL FACILITIES DISTRICT|REGIONAL TRANSPORTATION DISTRICT	80233, 80023, 80241, 80603, 80602, 80260, 80640, 80516, 80221, 80234, 80229	4.75%
WELD COUNTY|THORNTON CITY	80603, 80516	6.65%

How Does the Thornton Sales Tax Compare to the Rest of Colorado?

The lowest sales tax rate you can find in Colorado stands at 2.90%. The highest sales tax rate in the state is 11.55%. Here’s how Thornton’s sales tax rates compare against these rates:

• The minimum sales tax rate (4.75%) is 1.85% higher than the state's lowest rate and 6.80% lower than the highest rate.
• The maximum sales tax rate (6.65%) is 3.75% higher than the state's lowest rate and 4.90% lower than the highest rate.

To give you a better idea, here’s a comparison of Thornton sales tax rates with a few other cities in Colorado:

City	Sales Tax Rates
Vilas	2.90%
Thornton	4.75%-6.65%
Rangely	6.50%
Longmont	7.43%-8.72%
Nucla	8.65%
Lyons	9.19%
Snowmass Village	10.40%
Central City	8.90%-11.55%

You can also compare the sales tax rate of Thornton against the Colorado cities closest in population size:

• Fort Collins's sales tax rate is 8.05%
• Lakewood's sales tax rate is 7.93%

What Creates Sales Tax Nexus in Thornton?

Thornton has the same sales tax nexus rules as Colorado. 

Read More: Check out this detailed guide on Sales Tax in Colorado.

You have sales tax nexus in Thornton if you meet one of the following conditions:

• Physical nexus: Businesses with a physical location in Colorado must follow all sales tax licensing and collection rules if the retailer maintains any place of business in the state directly, indirectly, or by a subsidiary. A place of business may include an office, distribution center, salesroom, warehouse, storage space, or even a home office of a Colorado-based employee. 
• Employees: A retailer will have nexus through an employee who is a salesperson or a representative of the business.
• Economic nexus: Businesses must collect Colorado sales tax if their retail sales into the state during the current calendar year exceed $100,000. 

What Products Are Exempt from Thornton Sales Tax?

Thornton follows the same sales tax rules as Colorado and doesn't have any special exemptions. 

The items exempt from sales tax in Thornton are:

• Food purchased for human consumption, except for hot food ready to be eaten or heated in the store. 
• Gas, electricity, coal, wood, and fuel oil sold for residential use. 
• All prescription drugs dispensed by a practitioner with a valid prescription. 
• Certain medical supplies and materials.
• Farm equipment, such as farm tractors, irrigation equipment, dairy equipment, and more.

Who Needs a Sales Permit in Thornton?

You need a sales permit if you are a retailer located in Thornton or if you have a sales tax nexus.

You can register for a sales tax permit online via the Colorado Department of Revenue Website or offline by submitting form CR 0100. 

How to Collect Sales Tax in Thornton

Colorado is a destination-based sales tax sourcing state. 

This means that when you make a taxable retail sale to a customer in Thornton, whether from outside or within the state, you must apply the sales tax rate according to the buyer's shipping address.

Learn more about origin-based and destination-based sales tax sourcing here.

How to File and Pay Sales Tax in Thornton

You can file Thornton sales tax returns using the following methods:

• Automated: Let Zamp handle your Colorado sales tax filing and remittance so you won’t have to deal with sales tax returns ever again.
• Online: If you have more than one business location, you must file a separate return in the Revenue Online Website for each location.
• Approved Sales Tax Software: Vendors with multiple locations can use Approved Sales Tax Software, which will automatically generate electronic XML files that can be uploaded to Revenue Online.
• Sales Tax Spreadsheet E-Filing: Multiple location filers who don’t use the Approved Sales Tax Software can use Sales Tax Spreadsheet E-Filing.
• Offline: You can select the applicable forms and mail them to:
  Colorado Department of Revenue
  
  Denver, CO 80261-0013