Colorado Estimated Tax Payments: Deadlines, Safe Harbor, and Penalties

If you expect to owe Colorado at least $1,000 in income tax beyond what gets withheld from your paychecks, you have to make Colorado estimated tax payments in four installments across the year rather than settling up at filing time.1Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax The deadlines are April 15, June 15, September 15, and January 15 of the following year, and you can pay online through Revenue Online or by mail using Form DR 0104EP.2Colorado Department of Revenue. Individual Income Tax – Estimated Payments

Who Has to Pay

The rule triggers when your net Colorado tax liability, after subtracting withholding and credits, will reach $1,000 or more.1Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax “Net” matters here. It’s the tax you’ll actually owe after credits, not the gross figure, so credits you expect to claim count against the threshold.

Most people who end up making quarterly payments are self-employed, freelancing, running a rental, or living off investment income, interest, or dividends. W-2 employees land here too when their withholding doesn’t keep up with a side income or a working spouse. Both full-year residents and nonresidents with Colorado-source income are covered.3Colorado Public Law. Colorado Code 39-22-605 – Failure by Individual to Pay Estimated Income Tax If you moved into or out of Colorado during the year, you base the calculation on the income tied to your residency period plus any Colorado-source income from the rest of the year.

The Four Deadlines

Payments are due in four installments each year:2Colorado Department of Revenue. Individual Income Tax – Estimated Payments

  • First quarter: April 15
  • Second quarter: June 15
  • Third quarter: September 15
  • Fourth quarter: January 15 of the following year

When a due date falls on a Saturday, Sunday, or legal holiday, it rolls to the next business day.2Colorado Department of Revenue. Individual Income Tax – Estimated Payments Watch the spacing. Only two months separate the April and June payments, then three months to September. Calendar reminders set for “every three months” after April routinely miss the June deadline.

How Much to Pay Each Quarter

Start with your federal adjusted gross income, apply Colorado’s additions and subtractions, and arrive at Colorado taxable income. The 2025 rate is 4.40%.4Colorado Department of Revenue. Individual Income Tax Guide A temporary reduction mechanism under C.R.S. 39-22-627 can lower the rate in years when TABOR surplus revenue crosses certain thresholds, so confirm the current rate on the Department of Revenue site before you run numbers for 2026.5FindLaw. Colorado Code 39-22-627 – Temporary Reduction in Income Tax Rate

Multiply taxable income by the rate, subtract expected withholding and credits, and divide the remainder by four. That’s your baseline quarterly payment. If the non-withheld income starts partway through the year, you can spread the balance across the installments that haven’t come due yet instead of trying to make up the earlier quarters all at once.

Safe Harbor: Paying Enough to Avoid Trouble

Two safe harbors let you avoid the underpayment penalty regardless of how your actual liability lands.1Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax

The first is paying at least 70% of your current year’s net tax through withholding and estimated installments combined. That’s more forgiving than the federal 90% threshold, and it’s the figure to lean on when your income is hard to predict.

The second is paying 100% of last year’s Colorado liability, spread across the four installments. If your prior-year federal AGI topped $150,000 (or $75,000 if married filing separately), the figure rises to 110%. The prior-year method only works if your previous tax year ran a full twelve months and you filed a Colorado return for it.

If last year’s tax number is known and this year’s income is unpredictable, the prior-year method is the easier path. If your income dropped sharply, basing payments on 70% of the current year keeps you from overpaying.

How to Submit a Payment

Online Through Revenue Online

Revenue Online at Colorado.gov/RevenueOnline is the fastest option and doesn’t require an account.6Colorado Department of Revenue. Pay Online by Credit/Debit Card or E-Check From the homepage, choose “Make a Payment” under Payment Options, then pick e-check, debit card, or credit card. Select “Individual Income Tax” as the account type and “Estimated Payment” as the payment type, and enter the filing period as December 31 of the tax year you’re paying toward. Card payments carry a third-party processing fee; e-check doesn’t.

Save the confirmation number. It’s your proof the payment went through, and the Department will ask for it if timing is ever disputed.

By Mail

Mail a check or money order with Form DR 0104EP, the Individual Estimated Income Tax Payment Form, available on the Department of Revenue website.7Colorado Department of Revenue. DR 0104EP – Individual Estimated Income Tax Payment Form Write your Social Security number or ITIN, “DR 0104EP,” and the tax year on the check.8Colorado Department of Revenue. DR 0104EP 2026 Colorado Estimated Income Tax Payment Form Joint filers should use the name and SSN that will appear first on the return.

Mail to: Colorado Department of Revenue, Denver, CO 80261-0008. The ZIP is dedicated to the Department, so no street address is needed.8Colorado Department of Revenue. DR 0104EP 2026 Colorado Estimated Income Tax Payment Form Give the mail enough lead time to arrive by the deadline, not just be postmarked by it.

Adjusting Payments When Your Income Changes

Your original quarterly figure isn’t locked in. If income rises or falls during the year, recalculate your expected liability and change the amount you send next quarter. Colorado has no formal amendment process for estimated payments; you just send a different number.

For income that arrives unevenly, such as a seasonal business or a one-time payout, Colorado offers an annualized income installment method. You can only use it if you also elected it for your federal estimated taxes.1Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax Each quarterly payment is based on income actually received through the month before the due date, annualized and multiplied by a cumulative percentage:

  • April 15 installment: January through March income, times 17.5%
  • June 15 installment: January through May income, times 35%
  • September 15 installment: January through August income, times 52.5%
  • January 15 installment: January through December income, times 70%

Each installment is reduced by the payments you already made earlier in the year. Keep a schedule showing how you allocated the income; the Department of Revenue can ask for it.1Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax

The Penalty for Underpaying

Pay too little, and Colorado charges an underpayment penalty calculated as interest on the shortfall for each quarter it ran short. The 2026 rate is 11%, applied from each installment’s due date until the earlier of the payment date or the return filing deadline.3Colorado Public Law. Colorado Code 39-22-605 – Failure by Individual to Pay Estimated Income Tax The rate is set annually and has swung noticeably in recent years.

The penalty accrues quarter by quarter, so paying the full remaining balance with your September installment doesn’t erase interest already building on the April and June shortfalls. Catching up later limits future damage; it doesn’t undo past damage.

You avoid the penalty entirely if any of the following is true:1Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax

  • Your net Colorado tax after withholding and credits is under $1,000.
  • Your payments covered at least 70% of your current-year liability.
  • Your payments equaled 100% of your prior-year liability, or 110% if your prior-year AGI exceeded $150,000.

If You Overpay

When your installments add up to more than your actual tax, you choose at filing time between a refund and carrying the overpayment forward to the first installment of the next year. Overpayments can’t be refunded outside the return, so the money isn’t available until you file.

Boundaries: Corporations and Federal Taxes

C corporations follow a separate rule under C.R.S. 39-22-606: the exemption threshold is a tax liability under $5,000 rather than $1,000, and payments go on Form DR 0112EP instead of the DR 0104EP.9FindLaw. Colorado Code 39-22-606 – Failure by Corporation to Pay Estimated Income Tax

Paying Colorado doesn’t satisfy the IRS. If you expect to owe $1,000 or more in federal tax after withholding, you also make quarterly payments on Form 1040-ES, on the same April, June, September, and January calendar.10Internal Revenue Service. Estimated Taxes11Internal Revenue Service. Estimated Tax Federal safe harbors are tighter: 90% of the current year or 100% of the prior year (110% if prior-year AGI topped $150,000). Clearing the federal bar generally clears Colorado’s; the reverse isn’t reliable.