File Colorado Taxes Faster
Today, Colorado collects nearly $10 billion in taxes. Of this, over 50% comes from Colorado income taxes. The state has a flat tax rate of 4.4%. Residents (even part-time) must file a return if they earned income while living in the state. Non-residents with income that was earned inside the state are also required to file their taxes if they are also required to file a federal return. Taxes are due on April 15, as with federal returns, however if you were living or traveling outside of the country at that time, your tax deadline is automatically extended to June 15. Additionally, Colorado grants an automatic extension to file until October 15, though any taxes owed must still be paid by April 15 to avoid penalties and interest.
No Extension to File CO Taxes
Colorado will automatically extend the filing date for state tax returns to October 15th, regardless of whether you file for a federal extension. There is no additional tax extension paperwork to file. However, if you owe state taxes, you should attempt to pay at least 90% of this amount by April 15 in order to avoid additional late penalties and interest.
If you were traveling or living outside the country on the tax deadline and are waiting until June 15 to file, you'll still need to pay any taxes owed by April 15 to avoid interest charges, but you do not need to provide supporting information in order to avoid late payment penalties. If you were stationed in a combat zone on April 15, you have 180 days after your assignment in that combat zone ends to pay your taxes.
If you fail to file your taxes, you'll owe a penalty equal to the greater of $5 or 5% of the taxes due in April. You'll also pay an additional 0.5% per month in penalty (up to a maximum of 12%) and interest on the unpaid balance, which accrues separately and is adjusted annually. The same tax penalties apply for late payments unless you paid at least 90% of the balance due by April 15.
Check Your Colorado Tax Return or Amendment
You can check the status of a tax refund, return, or amendment by using the Revenue Online system. To access your account, you can sign in or create one using your name, Social Security number, or other identifying number, and mailing address. A Letter ID is only required if you are responding to a specific notice or verifying your identity — it is not necessary just to sign up for an account.
Mailing Addresses
For tax returns and/or amendments mail to:
Colorado Department of Revenue
Denver, CO 80261-0005.
If you have reason to suspect that you will owe more than $1,000 in income taxes, you must pay quarterly estimated payments.This applies if your withholding and credits will be less than the smaller of:
- 100% of your prior year’s tax liability, or
- 90% of your current year’s expected tax liability
Frequently Asked Questions
How long does it take to get a refund?
The speed of your refund will be related to how you filed your taxes. Typically, if filing by:
- E-file, expect between 3-5 weeks
- Paper, expect up to 3 months
Are past tax forms available?
Yes. Current and previous tax forms are available on the state's website. Forms published in 2021 and onward are fillable and savable.
If I'm not able to pay my tax bill in full, can I set up a payment plan?
Yes. You may go to the Department to request a payment plan (also known as an installment agreement or an agreement to pay). If approved, you'll be able to make monthly payments until your debt is fully paid.
Note: States & U.S. territories may make changes to their tax laws with little notice. We do our best to keep this information up-to-date, but it is provided on an "AS IS" basis. For more see our terms.