Colorado taxes your wages, investment income, and business earnings at a flat rate

Colorado has a flat state income tax rate of 4.63% on most income. This means whether you earn $30,000 or $300,000 per year, the state takes the same percentage. The rate applies to wages, self-employment income, capital gains, interest, dividends, and retirement distributions. Colorado does not have separate tax brackets like many other states — everyone pays the same percentage on taxable income.

The state income tax is separate from federal income tax. You file both a federal return (Form 1040) and a Colorado return (Form 104). The Colorado Department of Revenue collects the state tax. If you work in Colorado but live in another state, or live in Colorado but work elsewhere, different rules may apply depending on where you earned the money and where you claim residency.

Key Takeaways

  • Colorado's flat income tax rate is 4.63% on wages, self-employment income, capital gains, and most other income sources.
  • You file a separate Colorado state return (Form 104) in addition to your federal return each year.
  • Colorado offers a standard deduction that reduces your taxable income before the 4.63% rate is applied.
  • Certain types of income, including Social Security benefits and some retirement distributions, may be partially or fully exempt from Colorado state tax.
  • If you owe Colorado income tax, you typically pay through withholding from paychecks, quarterly estimated payments, or when you file your return.

Standard deduction and how it lowers what you owe

Before Colorado applies the 4.63% rate, you subtract a standard deduction from your income. The standard deduction amount depends on your filing status and age. For the 2024 tax year, the standard deduction ranges from about $3,850 for a single filer under 65 to higher amounts for married filers and those 65 and older. The Colorado Department of Revenue publishes the exact amounts each year on its website.

The standard deduction works like this: if you earn $40,000 and the standard deduction is $3,850, your taxable income is $36,150. Colorado then applies 4.63% to that $36,150, not the full $40,000. You can also itemize deductions instead of taking the standard deduction if your itemized deductions are larger, though most people benefit from the standard deduction.

Income that is fully or partially exempt from Colorado tax

Not all income is taxed at 4.63%. Social Security benefits are exempt — you do not pay Colorado state tax on them. Military retirement pay and certain federal employee retirement income also receive special treatment. Some distributions from retirement accounts, including traditional IRAs and 401(k)s, may be partially exempt depending on your age and total income.

If you are 55 or older and receive a pension from your employer, Colorado allows you to exclude up to $24,000 of pension income per year from state taxation (this amount changes annually). If you are 65 or older, the exemption is higher. These exemptions apply only to pensions and certain retirement income, not to wages or self-employment earnings. The Colorado Department of Revenue website lists the current year's exemption amounts.

How Colorado withholds tax from your paycheck

If you are an employee, your employer withholds Colorado state income tax from each paycheck based on a form you complete called the Colorado W-5. This is similar to the federal W-4 form. You tell your employer how much to withhold — you can claim allowances to reduce withholding or request extra withholding if you expect to owe money at tax time.

The amount withheld depends on your gross pay, filing status, and the allowances you claim. If you have multiple jobs, work part-time, or have a spouse who also works, you may need to adjust your withholding to avoid owing a large amount when you file. You can change your W-5 at any time by giving a new form to your employer's payroll department.

Self-employment income and quarterly estimated payments

If you are self-employed or have income that is not subject to withholding, you may need to make quarterly estimated tax payments to Colorado. These are payments you send to the state four times per year (roughly in April, June, September, and January) to cover the income tax you expect to owe. You calculate the amount based on your estimated income for the year and the 4.63% rate.

You do not have to make quarterly payments if you expect to owe less than $500 in Colorado state tax for the year. If you do owe more than $500 and do not make quarterly payments, you may owe a penalty when you file your return. The Colorado Department of Revenue provides a worksheet to help you calculate your estimated payment amount, and you can pay online through their website.

Filing your Colorado return and paying any remaining tax

You file your Colorado return by April 15 each year, the same deadline as your federal return. You use Form 104 (the Colorado Individual Income Tax Return) and attach schedules for any income that needs additional reporting. If you had taxes withheld from your paycheck or made quarterly payments, those amounts are credited against what you owe. If you overpaid, you receive a refund; if you underpaid, you owe the difference.

You can file your Colorado return on paper by mail or electronically through the Colorado Department of Revenue website or through tax software. Many tax preparation services and free tax preparation programs (like VITA, which serves lower-income filers) can help you file. If you file late or owe tax you do not pay by April 15, the state charges interest and penalties on the unpaid amount.

Tax credits that reduce what you owe Colorado

Colorado offers several tax credits that directly reduce the amount of tax you owe, rather than reducing your income before tax is calculated. A tax credit is worth more than a deduction because it subtracts directly from your tax bill. Common credits include the Colorado child dependent credit, the earned income tax credit (which mirrors the federal credit), and credits for property taxes or rent paid.

To claim a credit, you report it on your Form 104 return. Some credits are refundable, meaning if the credit is larger than the tax you owe, you receive the difference as a refund. Others are nonrefundable, meaning they can reduce your tax to zero but cannot create a refund. The Colorado Department of Revenue publishes a guide each year listing all available credits and who can claim them.

Frequently Asked Questions

Do I have to file a Colorado return if I only lived there part of the year?

If you were a Colorado resident for any part of the tax year, you must file a Colorado return on your income earned while you were a resident. If you moved to Colorado partway through the year, you file as a part-year resident and report only the income you earned after you moved. The Colorado Department of Revenue determines residency based on where you lived and your intent to stay.

What happens if I move out of Colorado — do I still owe state tax?

You owe Colorado state tax only on income you earned while you were a Colorado resident. Once you move and establish residency in another state, you no longer owe Colorado tax on new income. However, you must file a final Colorado return for the year you moved, reporting income only through the date you left the state. Some states have reciprocal agreements, so check with your new state's tax authority about whether you owe tax there.

Is the 4.63% rate the same every year?

The rate has been 4.63% since 2020, but Colorado law allows the rate to change. The state legislature can adjust the rate, and it has changed in the past. You can check the current year's rate on the Colorado Department of Revenue website. The rate applies to the tax year in which you earned the income, not the year you file the return.

Can I deduct federal income tax I paid from my Colorado taxable income?

No. Colorado does not allow you to deduct federal income tax paid. You calculate your Colorado taxable income starting from your federal adjusted gross income, but federal tax payments are not deductible. This is one reason your Colorado tax bill may be different from your federal bill even though both use similar income figures.

What if I disagree with a Colorado tax bill or notice?

You can file a protest with the Colorado Department of Revenue within 30 days of receiving a tax notice. The protest must explain why you believe the bill is wrong and include supporting documents. If the department denies your protest, you can appeal to the Colorado Board of Tax Appeals. The process is free, though you may want to consult a tax professional or attorney if the amount is large.