2024–2025 Tax Deadlines: Federal & Colorado
Staying on top of tax deadlines is one of the simplest ways to avoid unnecessary penalties and interest. Here's a consolidated calendar of the key dates that matter for Denver individuals and businesses.
Note: Deadlines occasionally shift when they fall on weekends or federal holidays. Always verify with the IRS or Colorado Department of Revenue for the most current information — or just ask us.
Individual Tax Deadlines
| Date | Deadline | Notes |
|---|---|---|
| January 15 | Q4 estimated tax payment due | Federal & Colorado |
| April 15 | Individual tax returns due (Form 1040) | Federal & Colorado DR 0104; Q1 estimated payment also due |
| June 16 | Q2 estimated tax payment due | Federal & Colorado |
| October 15 | Extended individual returns due | Only if extension was filed by April 15 |
Business Tax Deadlines
- January 31 — W-2s and 1099s must be furnished to recipients
- March 17 — S-Corp (Form 1120-S) and Partnership (Form 1065) returns due
- April 15 — C-Corp (Form 1120) returns due
- April 15 — Q1 estimated payments due
- September 15 — Extended S-Corp and Partnership returns due
- October 15 — Extended C-Corp returns due
Colorado generally mirrors federal business deadlines, but always confirm with your CPA or the Colorado Department of Revenue.