Colorado sales tax is filed online through Revenue Online, the Department of Revenue's portal, on the Retail Sales Tax Return (Form DR 0100). Monthly, quarterly, and annual returns are all due on the 20th of the month after the reporting period, and a return is required every period, even with no sales. Since January 1, 2026, Colorado has phased in mandatory electronic filing, starting with retailers that had $500,000 or more in gross sales in the prior calendar year.
This guide covers who files and how often, how to file in Revenue Online, what to do about Colorado's home-rule cities and special districts, how to report no sales, how to amend a return, how to pay, and what late filing costs.
This article is educational information, not tax advice. Filing rules, thresholds, and penalties can change, so confirm current requirements with the Colorado Department of Revenue before you file.
Colorado sales tax filing at a glance
- Who administers it: Colorado Department of Revenue, Taxation Division.
- Online portal: Revenue Online for state-collected sales tax. The Sales & Use Tax System (SUTS) remittance portal also files state, state-collected, and participating home-rule self-collecting returns in one place.
- Return: Retail Sales Tax Return, Form DR 0100. Each business location is reported on its own return.
- Filing frequency: Monthly, quarterly, or annual, based on the sales tax you collect.
- Due dates: The 20th of the month after the reporting period. If the 20th falls on a weekend or holiday, the due date is the next business day.
- Zero returns: Required every filing period.
- Payment: Electronic funds transfer (EFT), credit or debit card, e-check, or check or money order. EFT is required above $75,000 a year in state sales tax.
- Mandatory e-filing: Phased in from January 2026 by prior-year gross sales.
- Economic nexus: Retail sales into Colorado above $100,000 in the current calendar year.
Who has to file, and how often
If your business sells, rents, or leases tangible personal property in Colorado, you need a sales tax account (license) and must file sales tax returns. The Department notes that Colorado generally does not impose a state sales tax on services, though some home-rule cities charge a local sales tax on certain services.
Remote sellers are covered too. The Department says a retailer that did not exceed $100,000 in retail sales in the previous calendar year must begin collecting once its retail sales into Colorado exceed $100,000 in the current calendar year. The retailer then has 90 days after meeting the threshold to register, and collection begins on the first of the month following registration. Our Colorado sales tax guide covers registration and nexus in more detail. For a product-level example, see our post on Colorado clothing sales tax.
Sellers that only sell through a marketplace facilitator are not required to collect and remit state sales tax on those sales. If you also sell from your own website or a store, you are a multichannel seller and must collect and remit on those direct sales.
The Department's filing information page sets frequency by the sales tax you collect each month:
| Frequency | Sales tax collected | Due date |
|---|---|---|
| Annual | $50 or less per month | January 20 |
| Quarterly | Under $1,100 per month | April 20, July 20, October 20, and January 20 |
| Monthly | $1,100 or more per month | The 20th of the month following the period |
Wholesale businesses with a sales tax liability of $600 per year or less can file annually.
The Department assigns your schedule, and another page on its site lists lower cutoffs, so confirm the frequency shown on your own account in Revenue Online before you rely on the table.
Before you start: get into Revenue Online
You need a Colorado sales tax account (license) before you can file; our sales tax permit overview explains the process. To file through Revenue Online, you create your own user ID and password. Colorado also identifies each account by an eight-digit Colorado Account Number (CAN), which is different from your federal EIN.
Before filing, gather your gross sales by location for the period and any deductions or exemptions you claim. For wholesale sales, see our Colorado resale certificate guide for what to collect from buyers. If you sell in a new non-physical location, such as a jurisdiction you ship to, add it in Revenue Online before you start the return. Otherwise you will need to back out the return and begin again.
Step-by-step: filing a Colorado return in Revenue Online
- Log in to Revenue Online and open your sales tax account.
- Select File Return for the period currently due. To file an older period or amend, use File/Amend and View Returns/Payments and pick the period.
- Open each location. Each site has its own Gross Sales and Services amount, and deductions and exemptions apply only to that site. Enter site numbers on each return so the Department can allocate local jurisdiction tax correctly.
- Report gross sales, deductions, and exemptions using the correct version of the DR 0100 for the filing period. Do not leave lines blank; enter 0 where there is no amount.
- Review the return summary and any special district schedule.
- Submit and pay. Colorado requires you to report and pay to the penny.
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Home-rule cities, special districts, and rate pitfalls
Colorado's local layer is the hardest part of a return. The Department explains that local and special district sales tax is generally based on the rates for the destination address of the taxable sale. It also distinguishes two kinds of jurisdictions:
- State-collected jurisdictions: The Department collects for the state, statutory cities and counties, all special districts that assess a sales tax, and home-rule municipalities that have chosen to have the Department administer their tax. The Department lists 50 counties and approximately 150 municipalities, including 24 home-rule municipalities, plus all special districts.
- Self-collecting jurisdictions: Home-rule jurisdictions that do not make that election collect their own tax. The Department lists two counties and 72 municipalities as self-collecting. You contact them, or file through SUTS if they participate, rather than reporting their tax on your state return.
The Department publishes the current list of self-collecting jurisdictions, along with rates, in publication DR 1002, Colorado Sales/Use Tax Rates. You do not need to register separately with state-collected local jurisdictions to collect their tax, though some cities may require their own business license.
To find the right rate, use the Department's free SUTS geographic lookup tool, which returns state, county, municipal, and special district rates for an individual address. The Department announced in September 2026 that it will pause the SUTS bulk address lookup feature starting September 29, 2026, with the single-address lookup and filing portal unaffected. Colorado also has a hold-harmless provision: taxpayers who use a database certified by the Department are not liable for state and state-collected local tax owed only because the database designated the wrong jurisdiction. Our Colorado sales tax calculator shows current rates by location.
Due dates and the weekend rule
Monthly returns are due the 20th of the following month. Quarterly returns are due April 20 for January through March, July 20 for April through June, October 20 for July through September, and January 20 for October through December. Annual returns are due January 20. You can see them alongside other states on our Colorado sales tax due dates page.
If the 20th falls on a weekend or holiday, the due date is the next business day. In 2026, for example, the 20th lands on a Saturday in June and a Sunday in September and December.
Mandatory electronic filing
Under rules the Department adopted effective January 1, 2026, retail sales tax returns (DR 0100) must be filed electronically on this schedule, based on the retailer's annual gross sales or qualified purchases in the prior calendar year:
| Prior-year gross sales | Must file electronically starting |
|---|---|
| $500,000 or more | January 2026 filing periods |
| $50,000 or more | January 2027 filing periods |
| All retail sales tax returns | January 2028 filing periods |
The penalty for not filing electronically when required is the greater of $50 or 5% of the tax due.
Filing a zero return
You must file a sales tax return every filing period, even if you made no sales and collected no tax. If you do not, the Department files a return on your behalf and estimates the amount to be billed. To file a zero return in Revenue Online:
- Click File Return on your sales tax account.
- For each physical location, open the site and check the box verifying gross sales are $0.00. Physical locations show a red caution symbol.
- For non-physical locations, click File remaining non-physical sites as $0 returns.
- Confirm every site shows as filed, continue through the return summary and special district screens, then agree, submit, and enter your Revenue Online password.
If you no longer need the account, close it after you file your final return.
Amending a return
Mark the Amended Return box. The amended return must show every tax column as corrected, not just the difference, and it replaces the original return in its entirety. You can amend in Revenue Online. Use the correct service fee rate for the period you are amending. If you overpaid or have a credit from a mistake or canceled sale, you may take the credit on a later DR 0100. If you underreported, a separate return for the same period must be filed. A business that has closed applies for a refund using the Sellers Claim for Refund.
Payment methods
The Department lists these options for paying sales and use tax:
- Electronic funds transfer (EFT): Required for businesses that pay more than $75,000 a year in state sales tax.
- Credit or debit card or e-check: Available through the Department's payment pages.
- Check or money order: Include your eight-digit Colorado Account Number, the filing period dates, and the words Sales Tax Return. A federal EIN will not post the payment to your account.
State bills, such as a Statement of Account, can be paid only by check or money order with the voucher.
The service fee (vendor fee)
Colorado retailers used to keep a percentage of the tax collected as a service fee for timely filing. Under House Bill 25B-1005, beginning January 1, 2026, retailers may no longer retain the state sales tax service fee. Retailers may still be eligible to retain the service fee for local jurisdictions, and local rates are listed in DR 1002. For periods before 2026, the state service fee was capped at $1,000 and required the DR 0103 worksheet above that amount.
Penalties and interest for late payment
For sales tax, the penalty for failing to file, pay, or correctly account for the tax due is the greater of $15 or 10% of the unpaid tax plus one-half of one percent for each month the tax remains unpaid, not to exceed a total of 18%. Late payment of tax also results in disallowance of the service fee for periods where it applies.
Interest accrues from the original due date until the tax is paid. The Department publishes annual rates: for 2026, the discounted rate is 8% and the regular rate is 11%. The discounted rate applies if you pay before a notice of deficiency is issued, or pay or agree to pay within 30 days of the notice. Other penalties can apply for fraud, negligence, or making retail sales without a valid license.
Common mistakes to avoid
- Combining locations on one return. Each location is reported on its own DR 0100, with its own site number.
- Using an old form version. Use the DR 0100 for the correct filing period.
- Forgetting to add non-physical locations first. Set them up before starting the return.
- Ignoring self-collecting home-rule cities. Their tax is not on your state return.
- Skipping zero returns. Every period needs a return, even with no sales.
- Missing the e-file phase-in. Prior-year gross sales of $500,000 or more already require electronic filing.
More state filing guides
Filing in more than one state? These step-by-step guides cover the portals, due dates, and penalties in other states. See them all in our state-by-state guide to filing sales tax online.
- How to file Arizona sales tax online
- How to file Washington sales tax online
- How to file Texas sales tax online
Let Kintsugi file for you
If you sell in Colorado and other states, Kintsugi's sales tax filing software prepares and files returns on each state's assigned schedule and remits payment. Monitoring across every US state is free, so you know when you cross a threshold. Filing starts at $75 per filing, with no per-state subscription. See pricing, start free, or book a demo.
Frequently asked questions
Where do I file Colorado sales tax online?
In Revenue Online, on Form DR 0100. The Sales & Use Tax System (SUTS) portal also files state, state-collected, and participating home-rule self-collecting returns in one place.
What form do I use to file Colorado sales tax?
The Retail Sales Tax Return, Form DR 0100, filed in Revenue Online. Each business location is reported on its own return.
When is Colorado sales tax due?
Monthly and quarterly returns are due the 20th of the month after the reporting period, and annual returns are due January 20. If the 20th is a weekend or holiday, the due date is the next business day.
Do I have to file if I had no sales?
Yes. A return is required every filing period, including zero returns. In Revenue Online, verify $0.00 gross sales at each physical location and file non-physical sites as $0.
What is the economic nexus threshold in Colorado?
Retail sales into Colorado above $100,000 in the current calendar year. You have 90 days after meeting the threshold to register.
Do I report home-rule city tax on my state return?
It depends on the city. State-collected jurisdictions, including 24 home-rule municipalities, are collected by the Department. Self-collecting home-rule cities collect their own tax, so contact them directly or file through SUTS if they participate.
Sources
Checked September 29, 2026.
- Colorado Department of Revenue, Sales tax filing information
- Colorado Department of Revenue, Sales & use tax
- Colorado Department of Revenue, File sales tax on Revenue Online
- Colorado Department of Revenue, DR 0100 Retail Sales Tax Return
- Colorado Department of Revenue, Due date guide
- Colorado Department of Revenue, How to file a zero sales tax return
- Colorado Department of Revenue, Pay sales & use tax
- Colorado Department of Revenue, Service fee
- Colorado Department of Revenue, Sales & use tax FAQ
- Colorado Department of Revenue, Sales & Use Tax System (SUTS)
- Colorado Department of Revenue, Information for online sellers
- Colorado Department of Revenue, Tax topics: penalties and interest
