If you expect to owe at least $1,000 in federal income tax after withholding and credits, you must make quarterly estimated payments to avoid an underpayment penalty (IRC §6654). For 2026, the due dates are April 15, June 15, September 15, and January 15, 2027. The safe-harbor rule protects you from penalties if you pay 90% of your current-year tax or 100% of the prior year’s tax (rising to 110% if your 2025 AGI exceeded $150,000).
Use the self-employment tax calculator to estimate your quarterly payment based on your expected profit and filing status.
Who Must Pay Estimated Taxes
Estimated taxes are required when both conditions hold:
- You expect to owe at least $1,000 in federal tax for the year after accounting for withholding and refundable credits.
- Your withholding and refundable credits will cover less than 90% of your 2026 tax liability (or less than 100%/110% of your 2025 liability, whichever safe-harbor threshold you rely on).
Common situations requiring estimated payments:
- Self-employed workers (sole proprietors, single-member LLCs, partners)
- Freelancers and gig workers with 1099 income
- S corporation shareholders receiving distributions
- W-2 employees with large investment income, rental income, or side gigs
- Retirees with pension or Social Security income that is not adequately withheld
2026 Estimated Tax Due Dates
These are the standard quarterly due dates under IRC §6654(d)(1)(B). Check IRS.gov or Form 1040-ES 2026 for any adjustments when dates fall on a weekend or federal holiday.
| Quarter | Income Period | Payment Due |
|---|---|---|
| Q1 | January 1 – March 31 | April 15, 2026 |
| Q2 | April 1 – May 31 | June 15, 2026 |
| Q3 | June 1 – August 31 | September 15, 2026 |
| Q4 | September 1 – December 31 | January 15, 2027 |
Note that the quarters are unequal: Q1 covers 3 months, Q2 covers only 2, Q3 covers 3, and Q4 covers 4. This design dates from the original legislation; it affects the annualized installment method (Form 2210) but not the equal-fourths approach most taxpayers use.
Safe Harbor: Three Ways to Avoid Penalties
| Method | Rule |
|---|---|
| Safe harbor 1 (90% current) | Pay at least 90% of your actual 2026 tax, spread across the four quarters |
| Safe harbor 2 (100% prior) | Pay 100% of your 2025 tax if 2025 AGI was $150,000 or less |
| Safe harbor 3 (110% prior) | Pay 110% of your 2025 tax if 2025 AGI exceeded $150,000 |
Meeting any one of the three qualifies you. Safe harbors 2 and 3 are simpler because you can determine the amount from your 2025 return without projecting 2026 income. Divide the required amount equally across the four quarters.
Worked Example: $50,000 SE Profit
Assume a single filer with $50,000 net SE profit, no W-2 wages, no state income tax.
Tax calculation (from the engine):
| Component | Amount |
|---|---|
| Net earnings (×0.9235) | $46,175 |
| SE tax (SS 12.4% + Medicare 2.9%) | $7,065 |
| Half-SE deduction | $3,533 |
| AGI | $46,467 |
| Standard deduction | $16,100 |
| Federal taxable income | $30,367 |
| Federal income tax | $3,396 |
| Total federal liability (SE + income tax) | $10,461 |
Quarterly payment using equal-fourths method:
| Quarter | Due Date | Payment |
|---|---|---|
| Q1 | April 15, 2026 | $2,615 |
| Q2 | June 15, 2026 | $2,615 |
| Q3 | September 15, 2026 | $2,615 |
| Q4 | January 15, 2027 | $2,616 |
| Total | — | $10,461 |
Alternatively, if last year’s (2025) federal tax was $8,500 and your 2025 AGI was at or below $150,000, you can pay $8,500 ÷ 4 = $2,125 per quarter and be covered under safe harbor 2 — even if you owe $10,461 at filing.
State Estimated Taxes
Most states that have income taxes also require quarterly estimated payments, typically on similar schedules. California, New York, and many other states follow the same April/June/September/January cadence. Check your state’s department of revenue website for the exact amounts and due dates; state safe-harbor rules differ from federal ones.
How to Make Payments
The IRS accepts estimated payments through:
- IRS Direct Pay at IRS.gov — free, direct from your bank account
- Electronic Federal Tax Payment System (EFTPS) — recommended for regular payments and business use
- IRS2Go app
- Mail — check payable to “United States Treasury” with your SSN and “2026 Form 1040-ES” in the memo line
Pay each quarter separately even if you owe the same amount; EFTPS lets you schedule future payments in advance.
Adjusting Payments When Income Is Uneven
If your income is seasonal — for example, higher in Q3 and Q4 — the equal-fourths approach may cause you to overpay early quarters and underpay later ones. Form 2210 and its annualized income installment method let you match each quarter’s payment to actual income earned to that date rather than projecting a year’s total equally. This is more complex but reduces unnecessary early payments.
For SE tax calculation details, see self-employment tax explained. For a full comparison of 1099 vs. W-2 obligations, see 1099 vs. W-2 take-home pay.