You can file a Colorado tax return in two places: online through the Colorado Department of Revenue’s free Revenue Online portal, or on paper by mailing Form DR 0104 to the Department in Denver. The mailing address depends on whether you’re including a payment, and the online option is free whether or not you have an account.1Department of Revenue – Taxation. File Individual Income Tax Online2Colorado Department of Revenue. Contact Us By Mail
Filing Online Through Revenue Online
Revenue Online is the Department of Revenue’s own filing portal, available on the state’s website. You can prepare and submit your Colorado individual return there at no cost, and you don’t need to create an account or log in to file. Once your return has been processed, you can set up a login if you want to view your account history or manage future filings.1Department of Revenue – Taxation. File Individual Income Tax Online
If you’d rather use commercial tax software or hand everything to a paid preparer, that works too. Most major software programs support Colorado e-filing alongside your federal return.1Department of Revenue – Taxation. File Individual Income Tax Online
Mailing a Paper Return
Paper filers use Form DR 0104 and send it to the Colorado Department of Revenue in Denver. There are two addresses, and the one you use depends on whether a payment goes in the envelope:
- With payment: Colorado Department of Revenue, Denver, CO 80261-0006
- Without payment: Colorado Department of Revenue, Denver, CO 80261-0005
Include every required form and schedule in the same envelope. Missing attachments slow processing.2Colorado Department of Revenue. Contact Us By Mail A tracked service such as certified mail gives you proof of the date you sent it, which can matter if a filing date is ever questioned.
Paper returns take longer. The Department lists processing times of up to three months for mailed returns, compared with three to five weeks for e-filed ones.3Colorado Department of Revenue. Refund
Where Businesses File
Businesses use the same Revenue Online portal that individuals use. The system handles filing, amending, payment history, and account management. There’s one exception for first-time business income tax filers: your initial return must be filed on paper or through approved tax software, not through Revenue Online. After the Department processes that first return, you can create a Revenue Online login and use the portal from then on.4Department of Revenue – Taxation. Business Income Tax File Online
Where to Send a Payment
If you owe tax, Revenue Online accepts electronic payments by direct debit or by credit or debit card. Card payments carry a processing fee of 2.25% of the amount due plus $0.75.5Colorado Department of Revenue. Payment Frequently Asked Questions You can also mail a check or money order payable to the Colorado Department of Revenue with the appropriate payment voucher. If a check is going with a paper return, use the 80261-0006 address above so the payment and the return arrive together.
Keep in mind that Colorado’s automatic six-month extension to file does not extend the time to pay. To avoid a late-payment penalty, at least 90% of your total liability needs to be paid by April 15, even if the return itself goes in later.6Department of Revenue – Taxation. Individual Income Tax – Due Dates and Filing Extension
Where to Send an Amended Return
If you need to correct a return you’ve already filed, you can amend it electronically through Revenue Online at no charge. That option works even if you originally filed on paper, and it’s available for returns going back to 2009.7Department of Revenue – Taxation. Amending an Individual Income Tax Return
If you can’t amend online, file a paper Form DR 0104X. Use the version of the form that matches the tax year you’re correcting; the Department won’t process it otherwise.8Colorado Department of Revenue. Amended Colorado Individual Income Tax Return Instructions A mailed DR 0104X goes to the same Denver addresses as a DR 0104, chosen based on whether a payment is enclosed.
What to Do After You File
Hold on to a copy of your return and all supporting documents. Refund status is tracked through Revenue Online using your Social Security Number or ITIN, the exact refund amount, and the tax year. The Department’s phone agents see the same information the online tool shows, so calling won’t surface anything extra.3Colorado Department of Revenue. Refund
If You Receive an Identity Verification Letter
The Department sometimes flags returns for identity verification and sends a letter by mail with a validation key. Any phone call or email asking for this information is a scam; the Department contacts you only by mail.9Colorado Department of Revenue – Taxation. Taxpayer Identity Verification
You have 30 days to respond. Go to Revenue Online, open “Where’s My Refund?”, click “Provide Validation Key,” enter your last name and the key from the letter, and confirm whether you filed the return. If you didn’t file it, use the same tool to report it as fraudulent. Miss the 30-day window and your return won’t be processed, and any refund won’t be released, until you verify by email, fax, or mail with copies of a government-issued photo ID and a document showing your name and the address used on the return.9Colorado Department of Revenue – Taxation. Taxpayer Identity Verification