Filing your Colorado sales tax return is simple with the state’s online system. You can file and pay directly through the Colorado Revenue Online website, as long as your business is registered to collect and remit sales tax.
This guide will walk you through the step-by-step process of filing online so you can submit returns on time, avoid penalties, and stay compliant with Colorado’s sales tax rules.
What You Need Before Filing
Before filing your sales tax return, you must prepare specific records to ensure your report is accurate. Here are the standard documents required to file a sales tax return in Colorado:
- Colorado Taxpayer Account Number (Sales Tax License) – You’re required to provide your Colorado sales tax account number to file your sales tax return. Once your registration with the Colorado Department of Revenue (CDOR) is approved, you should receive your account details electronically.Additionally, a copy of your Colorado Sales Tax License will be sent via mail as well.
- Revenue Online Account Log-in Details – The primary way to file your Colorado sales tax return online is by logging onto your Colorado Revenue Online account. To access the site, ensure you have your log-in credentials ready (e.g., your username and password).
- Total Sales – Gather your total revenue during the filing period. This includes all sales, whether they’re taxable or not. Even if you currently have no sales records, you’re still required to file a return.
- Taxable Sales – Compile the total taxable sales your business made within the filing period. You’ll need this data to determine how much sales tax you owe and must pay for the filing period.
- Taxable Purchases – Verify the total amount of taxable purchases your business spent within the filing period. This applies to both in-state and out-of-state transactions.
- Local Sales Tax Report – Some cities in Colorado impose a local sales tax. Thus, if you have a nexus in those cities, you’re required to file a single return that reports the breakdown of sales by jurisdiction. To do so, you must add the locations or “sites” to your Colorado Revenue Online account. This also applies to non-physical locations for remote sellers doing business in Colorado. For additional guidance, visit the CDOR official webpage.
- Bank Account and Routing Number – Select which bank account you want to use for paying the due taxes in your report. Prepare your bank details and routing number ahead of time.
- Filing Frequency Schedule – The state assigns a specific due date for every registered business. To find out your designated schedule, refer to the information you received from the CDOR upon registration or by logging into your Revenue Online account.
Step-by-Step: How to File Colorado Sales Tax Online
Step 1. Go to the Revenue Online – State of Colorado website. Step 2. Enter your Account Credentials: Log in using your username and password. Check your shared email/phone number and input OTP, when applicable.
Step 3. Prepare your Ecommerce Sales Tax Data (e.g., Taxes Report from Shopify).
Step 4. On the dashboard, scroll down to the “Sales Tax” section and then click “File Return”.
Step 5. Choose the location(s) where sales are made from the given location list based on your sales tax report by clicking the Location ID.
Step 6. Enter the gross sales and applicable deductions made on that location based on your Ecommerce Sales Tax Report. Click “OK” once done. Do the same for all the sites included in your report.
Step 7. At the end of the same page, click on “File remaining non-physical sites as $0 returns” if they do not show up in your report. After that, click “Next”.
Step 8. Review the summary “Total Tax for All Sites Filed,” which should match the collected tax on your Ecommerce Sales Tax report. After confirming all information is correct, then you can click “Next”.
Step 9. Choose if you would like to make a payment or not. Enter the payment account information that you will use and other details. Click Next.
Step 10. Mark the “I Agree” check box if you are ready to submit. Click Submit.
Step 11. Enter your password again to confirm submission. After that, click OK.
Step 12. Keep a copy of the return and/or payment confirmation for your records. This serves as proof of successful submission.
Step 13. Save the confirmation in your preferred location for recordkeeping purposes. Keeping online records using Google Drive is a common option.
Helpful tip: If the filing process is interrupted by internet issues, website downtime, or other disruptions. You can always click on “Save and Submit Later” to avoid losing your progress.
NOTE: If you’re stuck or need more assistance, you can watch Colorado’s video tutorial.
Due Dates
In Colorado, your filing schedule and due dates generally change depending on your monthly collected sales tax. For guidance, refer to the table below.
| FREQUENCY | REQUIREMENT | REPORTING PERIOD | DUE DATE |
| Monthly | Monthly sales tax collections are more than $600 | Monthly | 20th day of the month following the reporting period |
| Quarterly | Monthly sales tax collections are less than $600 |
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| Annual | Monthly sales tax collection is $15 or less | January 1 – December 31 | January 1 |
Due Date Filing Extensions
In the event of natural disasters, the CDOR may grant filing and payment due date extensions. These extensions typically align with the Internal Revenue Service’s (IRS) tax relief announcements. It is important to note that even if the IRS grants an extension, affected taxpayers must still contact the CDOR if they receive a notice of deficiency for penalties and interest for a return filed or tax paid during the extension period. To check if any extensions have been declared, visit the IRS Newsroom for the latest updates. Otherwise, you can contact the CDOR for extension inquiries through the following options:- Messaging through the Revenue Online website
- Sending an email to dor_taxpayerservice@state.co.us
- Call for additional assistance via Taxpayer Helpline 303-238-SERV (7378)
- Respond to a notice of deficiency and follow the instructions in the notice
Timely Filing Discount
Some states give businesses a discount for collecting, filing, and remitting sales tax on time. In Colorado, businesses can claim their Service Fee or Vendor Fee. This discount is allowed on timely reported sales. How to Claim: Eligible filers can keep a percentage of their collected sales tax if their state’s net taxable retail sales aren’t greater than $1 million during the filing period. The maximum allowed Service Fee is capped at $1,000 per filing period. Typically, the method used and the percentage to calculate your claimable service fee may change periodically. As of 2025, the current state service fee rate is 4.00%. To keep up with the service fee rate or check additional instructions, visit the CDOR “Service Fee” page.Filing Amended Returns
If you filed an inaccurate report (e.g., miscalculated taxes, missing information, etc.), you can amend your return online. To do so, follow these simple steps:- Step 1: Log in through the Revenue Online website.
- Step 2: Locate the return you wish to amend. Afterward, select the “File/Amend and View Returns/Payment” option.
- Step 3: On the new page, find the return you want to amend under the “View/Manage Periods” section.
- Step 4: Select “View/Amend” under the “Actions to Be Taken” category. On the next page, select “Amend” in the top right corner of the page.
- Step 5: Choose the location where your return needs to be amended. Whenever you click on the location ID, this should prompt a pop-up screen. Select “Yes” under the category asking “Would you like to amend the return for this site?”
- Step 6: Now, you can correct the details previously submitted in your sales tax return. Carefully go through each field and adjust the information accordingly.
- Step 7: Once everything is complete, review the details and submit your amended return. If the return is underpaid, you must pay the missing due taxes as well. Repeat the steps for each location where you need to amend a return.
Refunds
Under Colorado’s Code of Regulations 39-26-703(2)(e), filers can deduct overpaid taxes on their next sales tax returns instead of requesting a refund. This is generally done by reporting a credit on the next return filed. If your business is no longer registered with the CDOR, or if the overpayment is for a significant amount that you cannot recoup through a deduction, the state instructs you to request a refund. There are two main methods for a seller/retailer to request a refund for a previous sales tax return overpayment. First, download the Form DR 0137 – Seller/Retailers Claim For Refund form. Complete the document and mail it to the address provided on the form. The second option involves utilizing the Revenue Online website. Refer to the instructions below:- Step 1: Before submitting a refund request, review the “Claim For Refund” instructions form first. This form specifies the necessary documentation for your claim.
- Step 2: Next, log in to your Revenue Online account.
- Step 3: Select “Additional Actions” in the menu.
- Step 4: Choose “Submit a Claim for Refund (DR 0137)” and then complete the fields.
- Step 5: Submit your claim and wait for the CDOR’s response. Do not mail a copy of the request.
Filing Zero Returns in Colorado
Colorado requires taxpayers to file returns even if they have no taxable sales to report. Failure to file a return results in the CDOR automatically filing the return on your behalf. This means the CDOR will also calculate the estimated balance you must pay, even if you made no taxable sales. This remains in effect until you file the correct zero return yourself. If you do not file a zero return after the CDOR sends a no-file notice, the state may close your tax account. At the same time, your sales tax license also becomes revoked. To prevent this, you have two solutions:- Close your Colorado sales tax account – If you no longer plan to do any business in Colorado, you can request the state to close your account. Consequently, this prevents any late filing penalties as well.
- File a zero sales tax return – If you wish to maintain your Colorado sales tax account, you must comply with the state’s requirements. For instructions on how to file a zero return, refer to the steps below.
- Step 1: Follow the same procedures as filing a normal return. This means you must log in through your Revenue Online account first.
- Step 2: Enter zero (0) in the appropriate fields to indicate that you are filing a zero sales tax return.
- Step 3: Remember that each location requires separate returns. Select the correct location where you want to file a zero return. If your sales tax account has non-physical locations, you have the option to click “File remaining non-physical sites as $0 returns.”
- Step 4: Review all the submitted information and ensure all locations are properly selected.
- Step 5: Complete any remaining sections and then submit your zero return.
Special Event Sales Tax Returns
In Colorado, businesses generally are allowed to partake in a “Special Sales Event.” This event permits sellers to make taxable sales at a location different from their normal place of operations. Examples of special event sales are trade shows, fairs, festivals, holiday markets, and antique shows. You must have a special events license to qualify as a seller during such events, unless the event organizer has obtained a license to collect and remit tax on behalf of the vendors. Moreover, you’re required to file your special event sales tax return on the 20th of the month following the month in which the special event began, if you have not remitted the sales tax collected to the event organizer. To file a special event sales tax return, there are 2 methods. First is filing by mail using the Form DR 0098 – Special Event Retail Sales Tax Return. Complete the necessary fields, then mail it to the address provided on the form. The next option involves using the Revenue Online website. Here are the instructions from the CDOR:- Go to the Revenue Online website. This situation does not require a login.
- Locate the “File a Special Event Sales Tax Return” option under the “Sales and Use Tax” category.
- Afterward, indicate the period of the event through the “Special Event Date” dropdown list.
- Review the displayed information thoroughly before proceeding to the next step.
- The site generally adds most events to the list and sorts them by location. However, not all special events have available online forms that you can use.
- If you can see the event you participated in, select it, then choose “Next.”
- Select the correct form applicable to your special event.
- If the event you attended isn’t found, select “Click here if the event you attended is not available.”
- Next, fill in all the required information in the fields until you complete all mandatory prompts. After that, you can now submit your special event sales tax return in Colorado.
Other Filing Methods in Colorado
If you’re having difficulties filing your Colorado sales tax return online, you can try other options.- File with TaxHero – Let expert accountants in TaxHero prepare your sales tax returns for you. We’ll take everything off your hands so that you can spend your time more efficiently managing your business.
- Spreadsheet Filing – If your business has multiple locations and doesn’t use any sales tax software for filing returns, Colorado presents this option. First, you must download the latest spreadsheet template to file via spreadsheet upload.For additional instructions on how to become an approved spreadsheet filer, see Colorado’s Spreadsheet Filing Handbook. You may also watch the state’s official video tutorial for more guidance.