The Colorado Department of Revenue offers free e-filing for many taxpayers through its Revenue Online program. Individuals can file a return for the current tax year, as well as prior tax years. To get started, visit the Revenue Online website. Colorado levies a flat 4.63% income tax rate. A flat rate means the tax rate does not go up or down depending on income, unlike the federal income tax rate.


In order to complete the e-filing process, taxpayers should have their Federal 1040, 1040A or 1040EZ form already completed. The Colorado tax return asks for adjusted gross income (AGI) found on federal tax returns. Taxpayers should also have W-2s and 1099s with Colorado income tax withheld. If the form does not show state income tax withheld, do not enter the form in Revenue Online.

E-filing has become a more popular option for taxpayers in recent years. According to efile.com, 86% of taxpayers filed their federal returns electronically in 2014. The IRS reported that more than 117 million federal tax returns were e-filed in 2014, out of a total number of almost 137 million tax returns.

"In my opinion, e-filing is no riskier than online banking or shopping," said Anne B. Cohen, associate professor of accounting at the University at Buffalo School of Management, in a statement. However, not all returns can be e-filed through the IRS or the state.

"Some very complex returns cannot be e-filed, generally because the e-file system used by the IRS does not support all of the required forms," said Jared Moore and Pete Frischmann, professors of accounting at Oregon State University College of Business, in a statement.

If doing your own taxes gives you the heebie-jeebies, the Centennial State also offers ample opportunities to find tax help. According to a study by WalletHub, Colorado was tied with Connecticut as the fifth-best state for finding tax help. Colorado had the second-highest number of accountants per capita, with 6.11 accountants per 1,000 people. Accountants in Colorado also filed an average number of 138 returns each, and more than 51% of Colorado residents paid for tax help.

Low-income taxpayers can also qualify for free tax help in Colorado. The Volunteer Income Tax Assistance (VITA) program is sponsored by the IRS and offers complimentary tax help for taxpayers making up to $53,000 per year. The VITA program can help taxpayers file the most common federal tax forms, with the exception of complex Schedule Cs for self-employment or complex Schedule Ds for capital gains or losses. VITA can also file Colorado state income tax forms.