File Colorado Taxes Faster

Stamp of Colorado

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 4.63%. Residents (even part-time) must file a return if they earned income while living in the state. Non-residents with income which was earned inside the state are also required to file their taxes. 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.

No Extension to File CO Taxes

Colorado will automatically extend the filling date for state tax returns to October 15th if you have filed for a federal extension (with us or otherwise). 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.

If you were traveling or living outside the country on the tax deadline and are waiting until June 15 to file, you'll 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 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 greatest of $5 or 5% of taxes due in April. You'll also pay an addition half percent in interest on the balance every month thereafter. The same tax penalties apply for late payments unless you paid 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. You must provide your name, social security or other identifying number, mailing address and letter ID from a recent Revenue Department letter in order 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.

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.

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