The Longmont sales tax rate is 3.53% at the city level, which combines with state, county, and district taxes for a total 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 collects its own sales and use tax directly rather than through the Colorado Department of Revenue, and a few of its rules differ from neighboring cities.
How the 8.865% Combined Rate Breaks Down
Every taxable purchase inside the Boulder County portion of Longmont stacks five separate levies:
- 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 8.865%.2Longmont. Sales and Use Tax Frequently Asked Questions
A small section of Longmont sits inside Weld County, where county-level rates differ. If a business address is near the county line, the combined rate depends on which county it falls in. The city’s sales tax office or the MuniRevs portal can confirm the right rate for a specific address.
What Longmont Taxes and What It Doesn’t
The 3.53% city rate applies to tangible personal property unless a specific exemption exists. The detail that surprises new residents: Longmont taxes groceries bought for home consumption at the full city rate. Neither the state of Colorado nor Boulder County taxes groceries, but home-rule status lets Longmont set its own rule, so the city tax adds 3.53% to your grocery bill.2Longmont. Sales and Use Tax Frequently Asked Questions
Prescription drugs and certain prosthetic devices are exempt. Services generally escape the tax 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 and bring it into Longmont for storage or use without paying local sales tax at the point of sale, and you owe use tax at the same 3.53% city rate. This commonly covers online purchases from retailers that don’t collect Longmont’s local tax, equipment bought at trade shows, and materials ordered from out-of-state suppliers.
The city collects the same revenue regardless of where the item was purchased. Businesses that regularly buy from outside vendors need to track those transactions and report use tax on their monthly returns. Individual consumers technically owe use tax as well, though enforcement focuses more heavily on business purchases.
Construction Use Tax
Construction and building materials used inside the city carry use tax at the same 3.53% city rate plus 1.335% to Boulder County, and the general contractor is typically responsible.3City 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 proves city and county tax has been covered, so material vendors won’t charge sales tax on those purchases.
- Pay as you go. The contractor keeps every receipt for materials bought outside the city, files a return with the city by the 10th of each month for the prior month’s purchases, and attaches all invoices and receipts to that return.
Falling short of the pay-as-you-go requirements is a code violation that can trigger penalties under Section 4.04.320 of the Longmont Municipal Code.3City of Longmont. Construction Use Tax For a major remodel or new build, working out which option costs less is worth a call to the sales tax office before pulling the permit.
If You’re Collecting the Tax: License and Filing
Anyone doing business in Longmont needs a city sales and use tax license before making sales. The requirement covers retailers, manufacturers, wholesalers, contractors, professionals, and service businesses.4City 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 for sole proprietors), the legal business name, 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
Returns and payments run through the MuniRevs online portal, which issues a digital confirmation receipt on submission. Paper returns are also accepted by mail to the city’s finance department.5City of Longmont. Pay My Sales and Use Tax
Returns are due by the 20th of the month following the reporting period. When the 20th falls on a weekend or holiday, the deadline moves to the next business day.5City of Longmont. Pay My Sales and Use Tax Missing the deadline triggers late fees, so a calendar reminder around the 15th gives a buffer.
Even months with zero taxable sales typically require a return showing no tax due. Skipping a filing because you had no sales is a common mistake that generates unnecessary penalty notices.
Remote Sellers Shipping Into Longmont
Businesses 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.6Colorado 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 rate on top of state tax. The city’s sales tax office can confirm whether a specific business meets the local nexus threshold.
Sales through a marketplace platform like Amazon or Etsy are generally handled by the platform as a marketplace facilitator, so the individual seller does not separately collect or remit Longmont tax on those sales. Sales through your own website or in person at events inside the city are different and require your own license and filings.