Colorado tax guide

Colorado taxes for self-employed workers in 2026

Colorado's flat rate and more forgiving 70% test make planning simpler than in most states.

Published by Cadus Labs LLC · Last updated November 9, 2026 · How we write these guides

Based on the Colorado Department of Revenue's 2026 Form DR 0104EP and other guidance from the state's tax agency.

Colorado estimated tax payments for 2026

You have to pay estimated tax if you expect to owe more than $1,000 in net Colorado tax for 2026 after withholding and credits. The required amount is the smaller of 70% of your actual net tax or 100% of last year's.

The form is Form DR 0104EP, and you can generally pay online instead of mailing it.

2026 Colorado estimated tax due dates for calendar-year filers
Payment	Due
First payment	April 15, 2026
Second payment	June 15, 2026
Third payment	September 15, 2026
Fourth payment	January 15, 2027

The 2026 worksheet uses Colorado's flat rate of 4.4%, which can be temporarily reduced in some years.

Your federal tax comes first

Wherever you live, self-employed income is subject to federal income tax and self-employment tax. A single filer with $60,000 of net profit and no other income owes about $12,037 in federal tax for 2026, or 20% of profit, before any state or local tax.

Federal estimated payments are due April 15, June 15, and September 15, 2026, and January 15, 2027. Use our 1099 tax calculator to run your own numbers.

Recordkeeping checklist

Set aside for federal and state tax from every payment you receive.

Make federal and state estimated payments if you expect to owe enough.

Keep receipts and a mileage log for everything you deduct.

Put each Colorado payment date on your calendar.

Free tools for this

Calculator

1099 and Self-Employment Tax Calculator

Enter your 1099 income and business expenses to estimate self-employment tax, federal income tax, and what to set aside each quarter. No sign-up, and nothing you type is saved.

Calculator

Quarterly Tax Set-Aside Calculator

Turn expected profit into a practical tax savings target, then use Cadus to keep income, expenses, deductions, receipts, and reports organized.

Template

Quarterly Tax Savings Worksheet

Use this worksheet to turn expected monthly profit into a practical tax savings target before estimated tax due dates arrive.

Template

Business Expense Log Template

Copy this table to start organizing business purchases, receipt proof, categories, and business purpose before moving records into Cadus.

Official sources

the Colorado Department of Revenue's 2026 Form DR 0104EP Colorado: individual estimated payments

Related guides

Self-employment tax guide

Self-Employment Tax

The self-employment tax rate is 15.3%. See who pays, how the 2026 wage base works, the deduction for half the tax, and a worked example.

Estimated tax guide

Quarterly Estimated Taxes

2026 estimated tax due dates, who has to pay, how to avoid the penalty, and a worked example for a self-employed worker earning $60,000.

Schedule C education

Schedule C Expense Categories

Every Schedule C expense line in plain English: what goes on each one, what doesn't, and the records to keep for self-employed workers.

Colorado Taxes FAQ

When do I have to pay Colorado estimated tax?

When are Colorado estimated payments due in 2026?

April 15, 2026, June 15, 2026, September 15, 2026, and January 15, 2027.

Cadus educational content is not tax, legal, or accounting advice. Tax rules can change, and individual facts matter. Review official guidance or speak with a qualified tax professional before filing.