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Colorado Business State Tax Extension I Fiduciaries Filing Guide

DR 0105EP | Estate/Trust Estimated Tax Payment Form  ·  Fiduciaries  ·  Business Filing Guide

Overview

Colorado fiduciaries—including estates and trusts—are subject to state fiduciary income tax requirements, administered by the Colorado Department of Revenue. Colorado automatically grants an extension to file with no application or form submission required.

Original Filing Deadline

The original due date for the Colorado Fiduciaries return is April 15, 2026. File or remit full payment by this date to remain in good standing.

Extension Granted Automatically

Colorado automatically grants a filing extension for Fiduciaries. The extended filing deadline is October 15, 2026. No application or form submission is required to receive this extension.

Payment Is Still Due by Original Deadline

The extension applies to filing only—it is not an extension to pay taxes owed. Any outstanding tax liability must be paid by the original due date of April 15, 2026 to avoid penalties and interest. Use the Colorado | Online Tax Extension Payment to pay electronically. For mail-in payments, use DR 0105EP | Estate/Trust Estimated Tax Payment Form and send to: Colorado Department of Revenue 1375 Sherman Street Denver, CO 80261-0008

Late Filing and Payment Penalties

• Failure to File: Greater of: 12% of tax due; 5% of tax due for first month, plus 1/2% for each additional month; or $5.
• Failure to Pay: Greater of: 12% of tax due; 5% of tax due for first month, plus 1/2% for each additional month; or $5.

Best Practices

• Estimate and pay your Colorado fiduciary tax by April 15, 2026 to avoid interest and penalties.
• No extension form is required—Colorado grants the extension automatically.
• Use the state online payment portal for fast, convenient electronic payment.
• Set a reminder to file your completed Colorado Fiduciaries return by October 15, 2026.

Final Thoughts

• Colorado’s automatic extension simplifies the process—no paperwork required. Pay any balance due by April 15, 2026 and file your return by October 15, 2026.
• Quick Reference Table
• State Abbreviation
• CO
• State Name
• Colorado
• Business Entity Type
• Fiduciaries
• Extension Status
• Approved Automatically
• Return Due Date
• April 15, 2026
• Extended Due Date
• October 15, 2026
• Other Information
• Colorado grants you an automatic 6-month extension to file your business tax return. The extension is NOT an extension to pay any taxes you may have due. Tax payments are due by the original return due date.
• Online Payment
• Colorado | Online Tax Extension Payment
• Payment Voucher Form
• DR 0105EP | Estate/Trust Estimated Tax Payment Form
• State Payment Agency
• Colorado Department of Revenue
• Mailing Address with Payment
• Colorado Department of Revenue 1375 Sherman Street Denver, CO 80261-0008
• Failure to File Penalties
• Greater of: 12% of tax due; 5% of tax due for first month, plus 1/2% for each additional month; or $5.
• Failure to Pay Penalties
• Greater of: 12% of tax due; 5% of tax due for first month, plus 1/2% for each additional month; or $5.

Working with a Tax Professional

Business tax returns are complex—a licensed CPA or Enrolled Agent can maximize deductions, ensure accurate calculations, and handle filing on your behalf. Here's how working with a TaxPro typically goes:

1. 1Get matched with a verified U.S.-based CPA or Enrolled Agent
2. 2Upload your business documents via secure drag-and-drop
3. 3Review and approve your return with upfront, transparent fees
4. 4Your TaxPro files your Colorado return by October 15, 2026

Quick Reference Table

State Abbreviation	CO
State Name	Colorado
Business Entity Type	Fiduciaries
Extension Status	Approved Automatically
Return Due Date	April 15, 2026
Extended Due Date	October 15, 2026
Other Information	Colorado grants you an automatic 6-month extension to file your business tax return. The extension is NOT an extension to pay any taxes you may have due. Tax payments are due by the original return due date.
Online Payment	Colorado | Online Tax Extension Payment
Payment Voucher Form	DR 0105EP | Estate/Trust Estimated Tax Payment Form
State Payment Agency	Colorado Department of Revenue
Mailing Address with Payment	Colorado Department of Revenue 1375 Sherman Street Denver, CO 80261-0008
Failure to File Penalties	Greater of: 12% of tax due; 5% of tax due for first month, plus 1/2% for each additional month; or $5.
Failure to Pay Penalties	Greater of: 12% of tax due; 5% of tax due for first month, plus 1/2% for each additional month; or $5.