The Longmont sales tax is 3.53% at the city level, which stacks with state, county, and district taxes for a combined rate of 8.865% on most purchases in the Boulder County portion of the city.1City of Longmont. Sales and Use Tax Longmont is a home-rule municipality, so the city administers and collects its own sales and use tax rather than routing it through the Colorado Department of Revenue. That independence is why some rules here differ from surrounding cities.
How the 8.865% Combined Rate Breaks Down
Every taxable purchase in Longmont carries layers from five separate jurisdictions:
- City of Longmont: 3.53%
- State of Colorado: 2.90%
- Boulder County: 1.335%
- Regional Transportation District (RTD): 1.00%
- Scientific and Cultural Facilities District: 0.10%
Those pieces add to the 8.865% combined rate.2Longmont. Sales and Use Tax Frequently Asked Questions The county share alone funds a dozen voter-approved levies covering open space, transportation, affordable housing, wildfire mitigation, emergency services, and behavioral health.3Boulder County. Sales and Use Tax
A small slice of Longmont extends into Weld County, where county rates differ. If your address sits near the county line, the exact combined rate depends on which county it falls in. The city’s sales tax office or the MuniRevs portal can confirm the rate tied to a specific address.
What Longmont Taxes (and the Grocery Surprise)
The 3.53% city rate applies to tangible personal property unless a specific exemption exists. The detail that catches most residents: Longmont taxes groceries purchased for home consumption at the full city rate. Colorado and Boulder County do not tax groceries, but home-rule status lets Longmont set its own rule here, so the city’s 3.53% still lands on your grocery receipt.2Longmont. Sales and Use Tax Frequently Asked Questions
Prescription drugs and certain prosthetic devices are exempt. Services generally are not taxed unless they involve delivering or creating a physical product. Charitable, nonprofit, and tax-exempt organizations may qualify for exemptions but still need a city tax license on file.1City of Longmont. Sales and Use Tax
Use Tax on Purchases Made Outside Longmont
Buy something outside the city, bring it into Longmont for storage or use, and pay no Longmont sales tax at the point of sale? You owe use tax at the same 3.53% city rate. This most often hits online purchases from retailers that don’t collect Longmont’s local tax, equipment picked up at trade shows, and materials ordered from out-of-state suppliers.
The idea is simple: the city collects the same revenue no matter where the item was purchased. Businesses that regularly buy from outside vendors need to track those transactions and report the use tax on their monthly returns. Individuals technically owe it too, though enforcement leans heavily toward business purchases.
Construction Use Tax for Building Projects
Longmont charges use tax on construction and building materials used within city limits, and the general contractor is typically responsible for paying it. The rates are 3.53% to the city and 1.335% to Boulder County.4City of Longmont. Construction Use Tax
Contractors pick one of two methods:
- Lump sum at permit time. The taxable amount is calculated as 50% of the general or mechanical contract cost. Once paid, the permit copy serves as proof, so city and county sales tax will not be charged again on materials.
- Pay as you go. Keep all receipts for materials bought from any source outside the city, file a return with the city by the 10th of each month, and pay the use tax due for the prior month. Every invoice and receipt must be attached to the return.
Failing to follow the pay-as-you-go rules is a code violation that can trigger penalties under Section 4.04.320 of the Longmont Municipal Code.4City of Longmont. Construction Use Tax For a major remodel or new build, working out which method costs less is worth a call to the sales tax office before you pull the permit.
Sales Tax License for Businesses
Anyone doing business in Longmont needs a city sales and use tax license before making sales. That covers retailers, manufacturers, wholesalers, contractors, professionals, and service businesses.5City of Longmont. Forms for Doing Business in Longmont The one-time processing fee is $25, payable by cash or check.1City of Longmont. Sales and Use Tax
The application asks for your Federal EIN (or Social Security Number if you’re a sole proprietor), the legal name of the business, any trade name, the physical business address, and a description of the products or services you offer. That description helps the finance department classify your account for future reporting.2Longmont. Sales and Use Tax Frequently Asked Questions
Filing and Payment Deadlines
Longmont uses the MuniRevs online portal for electronic filing and payment of sales and use tax returns, with an immediate digital confirmation receipt when you submit.6City of Longmont. Pay My Sales and Use Tax Paper returns are also accepted by mail to the city’s finance department, though electronic filings process faster.
Returns and payments are due by the 20th of the month following the reporting period. If the 20th falls on a weekend or holiday, the deadline shifts to the next business day.6City of Longmont. Pay My Sales and Use Tax Missing the deadline triggers late fees. A calendar reminder around the 15th gives you enough of a buffer to pull records and file without scrambling.
The municipal code uses your start date of business operations to set your first filing period. Even a month with zero taxable sales usually still requires a return showing no tax due. Skipping a filing because you had no sales is a common mistake, and it generates unnecessary penalty notices.
Selling Into Longmont From Outside Colorado
Businesses located outside Colorado must collect Colorado sales tax once their annual retail sales into the state exceed $100,000 in either the current or previous calendar year.7Colorado Department of Revenue. Out-of-State Businesses Because Longmont self-administers its tax, remote sellers may face a separate obligation to register with the city and collect the 3.53% local tax on top of the state rate. The city’s sales tax office can confirm whether a specific business meets the local nexus threshold.
If you sell through a marketplace platform such as Amazon or Etsy, the platform typically handles sales tax collection and remittance as a marketplace facilitator, so the individual seller generally does not separately collect or remit Longmont sales tax on those platform-facilitated sales. Sales through your own website or in person at events within city limits are handled differently and require your own license and filings.