If you expect to owe more than $1,000 in Colorado income tax after withholding and credits, you need to make Colorado estimated tax payments four times a year: April 15, June 15, September 15, and January 15 of the following year.1Colorado Department of Revenue – Taxation. Individual Income Tax – Estimated Payments Each installment should cover one quarter of your required annual payment, which is the smaller of 70% of this year’s actual tax or 100% of last year’s (110% if your prior-year federal AGI topped $150,000).2Justia Law. Colorado Code 39-22-605 – Failure by Individual to Pay Estimated Income Tax Miss those targets and the state charges 11% interest on the shortfall, calculated separately for each quarter.
Who Has to Pay
With Colorado’s flat 4.4% rate applied to federal taxable income, the $1,000 threshold arrives faster than many first-time filers expect. The requirement typically catches people with freelance or independent contractor earnings, rental income, capital gains, alimony received, or business profits that don’t run through payroll withholding.3Colorado Department of Revenue. DR 0104EP – 2026 Colorado Estimated Income Tax Payment Form
Individuals, estates, and trusts with Colorado-source income all fall under the rule. Part-year residents and nonresidents who earn income in Colorado must also pay, but they apportion their income to determine the Colorado share before applying the tax rate.
The Four Due Dates
- First quarter: April 15
- Second quarter: June 15
- Third quarter: September 15
- Fourth quarter: January 15 of the following year
The quarters are not evenly spaced. April to June is two months; June to September is three. If a due date falls on a weekend or legal holiday, it shifts to the next business day.1Colorado Department of Revenue – Taxation. Individual Income Tax – Estimated Payments For mailed payments the postmark controls; for electronic payments, the timestamp does.
How Much to Pay Each Quarter
Colorado gives you two ways to avoid a penalty, and you only need to hit one. Your required annual payment is the lesser of:2Justia Law. Colorado Code 39-22-605 – Failure by Individual to Pay Estimated Income Tax
- 70% of your current year’s actual Colorado tax, or
- 100% of the prior year’s Colorado tax, provided last year was a full 12-month tax year and you filed a Colorado return.
The prior-year safe harbor has an income cap that trips people up. If your federal adjusted gross income on the prior year’s return exceeded $150,000 ($75,000 if married filing separately), the safe harbor rises to 110% of the prior year’s tax.2Justia Law. Colorado Code 39-22-605 – Failure by Individual to Pay Estimated Income Tax After a strong income year, matching last year’s payment dollar for dollar is not enough; bump it up by 10%.
Divide the required annual payment by four, and that’s your quarterly installment.4Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax To build the current-year estimate from scratch, multiply expected federal taxable income by 4.4%, then subtract Colorado credits and any employer withholding.3Colorado Department of Revenue. DR 0104EP – 2026 Colorado Estimated Income Tax Payment Form If what remains tops $1,000, compare the two safe harbor amounts and use the smaller one.
How to Pay
Revenue Online
The Colorado Department of Revenue’s Revenue Online portal is the fastest option, and you don’t need to create an account to make a payment. Choose credit card, debit card, or e-check. E-checks pull directly from your bank account using routing and account numbers. Card payments carry a processing fee charged by the third-party processor, not the state.1Colorado Department of Revenue – Taxation. Individual Income Tax – Estimated Payments Save the confirmation number; it’s your proof if the state ever disputes receipt.
By Mail
Download Form DR 0104EP and mail it with a check or money order to Colorado Department of Revenue, Denver, CO 80261-0008. Write your Social Security number (or ITIN) and “2026 DR 0104EP” on the check, and make sure the amount on the check matches the form.3Colorado Department of Revenue. DR 0104EP – 2026 Colorado Estimated Income Tax Payment Form For joint filers, submit the payment under the name and SSN that will appear first on the return, so it posts to the right account.
Prior Year Overpayment
If you carried an overpayment forward from last year’s return rather than taking the refund, it applies automatically to this year’s first estimated payment. It reduces the first installment first, with any excess rolling to the second, then the third, until used up. When you file, report only the portion applied to estimated taxes, not any part received as cash.
If Your Income Arrives Unevenly
Equal quarterly installments assume you earn at the same pace all year. For project-based freelancers, seasonal businesses, and anyone with a lopsided earnings calendar, that forces payments on money you haven’t made yet. Colorado’s annualized income installment method recalculates each installment based on income actually received through the end of the month before the due date.4Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax
You can only use this method for Colorado if you also elected it on your federal return. The required cumulative percentages are 17.5% by April 15, 35% by June 15, 52.5% by September 15, and 70% by January 15. Keep your annualization worksheets; the Department of Revenue can request them.4Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax
Farmers and Fishermen
If at least two-thirds of your gross income in either the current or preceding tax year comes from farming or fishing, Colorado replaces the quarterly schedule with a single payment due January 15 of the following year. The safe harbor is also more generous: the lesser of 50% of this year’s actual Colorado tax or 100% of last year’s (again assuming a 12-month prior year and a filed return).4Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax
What a Shortfall Costs
When estimated payments fall short, Colorado charges interest on each quarter’s underpayment for the period it stayed unpaid. The 2026 rate is 11%, running from the missed installment’s due date until the earlier of the payment date or April 15 of the following year.2Justia Law. Colorado Code 39-22-605 – Failure by Individual to Pay Estimated Income Tax
No penalty applies if your net tax liability after withholding and credits comes in under $1,000, or if you satisfy either safe harbor.4Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax Because the calculation runs quarter by quarter, overpaying the third and fourth installments doesn’t erase penalties already accrued on the first and second. If you realize mid-year that your income is running higher than planned, increasing the remaining payments limits the damage going forward, but it won’t retroactively repair earlier shortfalls.