Missing an IRS quarterly estimated tax deadline can cost you hundreds in unnecessary penalties. For 2026, the four deadline dates are fixed — but three of them land on weekends or holidays, triggering automatic adjustments. Here's the complete schedule.
2026 Quarterly Tax Deadlines
| Quarter | Original Date | Adjusted Date | Status |
|---|---|---|---|
| Q1 | April 15, 2026 | April 15, 2026 (Wednesday) | No adjustment needed |
| Q2 | June 15, 2026 | June 15, 2026 (Monday) | No adjustment needed |
| Q3 | September 15, 2026 | September 15, 2026 (Tuesday) | No adjustment needed |
| Q4 | January 15, 2027 | January 15, 2027 (Friday) | No adjustment needed |
Set it now: Block out April 10, June 10, September 10, and January 10 in your calendar — five days before each deadline — to give yourself buffer time to calculate and pay.
How to Calculate Your Quarterly Payments
The IRS uses two safe harbor methods to determine penalty-free payments:
- 90% of current year tax: Pay 22.5% of your estimated 2026 tax per quarter
- 100% of prior year tax: Pay 25% of what you owed for 2025 per quarter (110% if your 2025 AGI was over $150,000)
Common mistake: Freelancers often skip Q1 because "I haven't earned much yet." The IRS doesn't care — the penalty runs from April 16 regardless of your income during Q1.