Starting a business in Thornton, Colorado: a practical checklist

Updated

Thornton does something many Colorado cities do not: it runs its own sales tax and its own business license, separate from the state's. Requirements, fees and rules change, so confirm each step with the linked office before you act. This is general information, not legal or tax advice.

Start with the city license, not just the state

The City of Thornton's business licenses page says everyone engaged in business in Thornton must hold a City Sales and Use Tax Business License. That can include businesses based elsewhere that sell taxable services to Thornton residents or do service work under maintenance agreements. The page lists no fee for the license and no annual renewal, and you apply through the online portal at salestaxonline.com. Apply before you open.

The city has separate application packets for commercial locations, home-based businesses, vending businesses and tax-exempt organizations, so pick the one that matches your setup. Questions go to the Sales Tax Division at 303-538-7400 or [email protected].

Some businesses need more than that license. The city names liquor sellers, pawnbrokers and massage therapists as examples and sends you to the City Clerk's office at 303-538-7230 to find out what applies to your type of business.

Two sales tax accounts: Thornton and Colorado

Thornton describes itself as a home-rule city that collects its own 3.75 percent city sales tax. The remainder goes to the Colorado Department of Revenue. The city's sales and use tax rates answer breaks down the combined rate and notes a separate lodging tax on short room stays, so read it for current numbers rather than trusting a figure copied elsewhere. Thornton's taxes explained page also lists the Adams County portion.

In practice, a retailer here needs both:

  1. A Colorado sales tax license. The Department of Revenue explains how to apply through MyBizColorado or form CR 0100, and its standard retail license page covers the details.
  2. The City of Thornton license above, with city tax returns filed with the city rather than the state.

Keep the two filings straight from day one. Mixing them up is the easy mistake in a self-collected city.

Commercial space: occupancy and zoning

If you lease or buy a space in the city, the license page says commercial businesses need a certificate of occupancy inspection before opening, with a $25.00 fee due when you submit the application. Building Department questions go to 303-538-7250.

For what you may do on a given property, the city's zoning districts, uses and regulations page points to the Development Code, and says the page is not exhaustive. City Development is at 303-538-7295 or [email protected]. Ask them before you sign a lease.

Working from home

Thornton has a dedicated home-based business application packet, so a home business is licensed like any other. The limits on home occupations depend on your address and zoning, so check with City Development about what your address allows.

Register your entity with Colorado

Forming an LLC means filing Articles of Organization with the Colorado Secretary of State. The fee schedule lists $50 online for Articles of Organization and $25 online for the annual Periodic Report. It was last revised July 1, 2024 and is subject to change, so check it when you file. Start at sos.state.co.us.

Free help close to home

  • Thornton Office of Economic Development. It lists small business counseling, legal consultations, financial assistance programs, workshops and networking events on its small business support page. The main office is at 9500 Civic Center Drive, 303-538-7605, [email protected].
  • Alliance Business Center. The city runs this center at 550 E Thornton Parkway, Suite 170, with consulting, workshops and help finding grants. Contact 720-674-3547 or [email protected].
  • Colorado SBDC. The North Metro Denver SBDC, hosted by Front Range Community College, serves Adams and Broomfield counties, and lists a satellite advisor at the Alliance Business Center by appointment.
  • Thornton Area Chamber of Commerce. Networking events, a member directory and advocacy, at thorntonareachamber.com. Note that its office is listed in Northglenn.

Setting up a business email

You will need one address for the state, the city, your bank and your customers. The most flexible route is your own domain with Google Workspace or Microsoft 365: you own the name, and you can add staff. We offer a shorter alternative, an address like [email protected]. A personal name is $19 a month, trade names such as plumber@ cost more, there is no domain or DNS to set up, and it takes about five minutes. The tradeoff is that you rent the address rather than own the domain, so a brand with employees is better served by its own domain. The cost guide compares the options, or check a name on the home page.

Check a name or try the email address ideas tool.