Colorado Self-Employment Tax Calculator Tax Year 2026

Colorado Freelancer Tax Guide for 2026

Colorado State Income Tax for Freelancers

Colorado imposes a flat 4.40% state income tax on freelance and self-employment income (rate set by Proposition 116 in 2020 and Proposition HH adjustments since). Colorado's tax base starts with federal taxable income, so federal deductions including QBI and the half-SE deduction flow through to reduce Colorado tax — making it one of the more freelancer-friendly states procedurally.

Colorado Pass-Through Entity Tax (SALT Parity Act)

Colorado enacted a PTE tax election in 2021. S-Corps and partnerships pay state tax at the entity level (4.40%) and the federal deduction bypasses the SALT cap. Owners receive a corresponding refundable Colorado tax credit on their personal return for their share of PTE tax paid, so net CO tax is roughly unchanged — the federal deduction is what's unlocked. For CO S-Corp freelancers earning $175K+, federal savings typically run $500–$1,500/year. The election is annual and made on Form DR 1705.

Quarterly Estimated Payments in Colorado

Colorado quarterly estimates align with the federal schedule (April 15, June 15, September 15, January 15). File Form DR 0104EP. Safe harbor is 100% of prior year liability or 70% of current year. Underpayment penalty is calculated on Form DR 0204 at the federal short-term rate plus 3%.

Common Colorado Freelancer Gotchas

Several Colorado cities (Denver, Aurora, Glendale, Greenwood Village, Sheridan) impose an Occupational Privilege Tax (OPT) — a flat $5.75/month per employee plus $4.00/month employer fee in Denver, for example. This applies to S-Corp owners taking salary in those cities. Sole proprietors filing Schedule C are generally not subject to OPT. Denver also has its own sales tax structure layered on state sales tax, which can affect freelancers selling products. Colorado offers TABOR refunds in years with surplus revenue — these aren't predictable but reduce effective state tax.