Core Deadlines at a Glance
| Deadline | Date | What’s Due |
|---|---|---|
| W-2 / 1099 distribution | January 31, 2025 | Employers send you your forms |
| 1st estimated tax payment | April 15, 2025 | Q1 estimated taxes for self-employed |
| Tax return deadline | April 15, 2025 | File or request extension |
| Extension deadline | October 15, 2025 | Return with extension (tax owed still due April 15) |
| 2nd estimated tax | June 16, 2025 | Q2 estimated taxes |
| 3rd estimated tax | September 15, 2025 | Q3 estimated taxes |
| 4th estimated tax | January 15, 2026 | Q4 estimated taxes |
What If April 15 Falls on a Weekend?
The deadline moves to the next business day. In 2025, April 15 is a Tuesday, so the deadline is April 15.
Automatic Extension: Form 4868
Filing Form 4868 gives you until October 15, 2025 to file your return. Important: this is an extension to file, not to pay. Any tax you owe must still be paid by April 15 to avoid late-payment penalties (0.5% per month) and interest.
Estimated Tax Payments
If you’re self-employed, have significant investment income, or other income without withholding, you’re generally required to pay estimated taxes quarterly. Underpayment can trigger a penalty.
Safe harbor rules: Pay at least 90% of current year tax OR 100% of prior year tax (110% if prior year AGI > $150,000).
Penalties for Missing Deadlines
- Failure to file: 5% of unpaid tax per month, up to 25%
- Failure to pay: 0.5% per month, up to 25%
- Underpayment of estimated tax: Based on federal short-term rate + 3%
State Deadlines
Most states align with the federal April 15 deadline, but some differ. Check your state’s Department of Revenue website for exact dates.