Self-employed individuals, freelancers, and small business owners in the US pay taxes four times a year through quarterly estimated tax payments. Miss a quarterly deadline and you'll owe penalties — even if you pay the full amount by April. The 2026 quarterly due dates fall in April, June, September, and January, and each covers a specific three-month earning period. Knowing the exact dates keeps you penalty-free.

Let's walk through the 2026 quarterly tax schedule, how to calculate each payment, and the penalty for missing deadlines.

The 2026 Quarterly Tax Due Dates

Quarterly estimated taxes (Form 1040-ES) are due on the 15th of April, June, September, and January. Here are the 2026 deadlines and the earning periods each covers:

  • Q1 payment: April 15, 2026 — covers January, February, March 2026 earnings.
  • Q2 payment: June 15, 2026 — covers April and May 2026 earnings.
  • Q3 payment: September 15, 2026 — covers June, July, August 2026 earnings.
  • Q4 payment: January 15, 2027 — covers September, October, November, December 2026 earnings.

Notice the Q2 payment covers only two months (April-May), while Q4 covers four months (September-December). This uneven split is a quirk of the IRS schedule — the quarters aren't equal. If a due date falls on a weekend or holiday, it shifts to the next business day.

Who Needs to Pay Quarterly

You must pay quarterly estimated taxes if you expect to owe at least $1,000 in tax for the year and your withholding and credits cover less than 90% of your current-year tax (or 100% of your prior-year tax, whichever is smaller). This typically applies to:

  • Self-employed individuals and freelancers with no employer withholding.
  • Small business owners (sole proprietors, single-member LLCs, partners).
  • Investors with significant dividend, interest, or capital gains income.
  • Employees with insufficient withholding — often from a side business or second job.

If you're a W-2 employee with no other income, you usually don't need to pay quarterly — your employer's withholding covers it.

How to Calculate Each Payment

The simplest method is the "safe harbor" rule: pay 100% of your prior-year tax liability (110% if your adjusted gross income was over $150,000), split into four quarterly payments. This protects you from underpayment penalties even if your current-year income is higher.

The more precise method: estimate your current-year taxable income, calculate the expected tax, subtract withholding and credits, and divide the remainder across the four quarters based on when you earn the income. The IRS provides Form 1040-ES worksheets to walk through this.

For uneven income (common in seasonal businesses), use the annualized income method (Form 2210) to match payments to when you actually earn the money. This avoids overpaying early in the year when income is low.

Penalties for Missing Quarterly Deadlines

The IRS charges an underpayment penalty if you don't pay enough tax throughout the year. The penalty is calculated like interest on the underpaid amount, using the federal short-term rate plus 3%. For 2026, the rate is around 8% annually — meaning a $10,000 underpayment for a full year costs roughly $800 in penalties.

The safe harbor rules protect you from penalties: if you pay 100% of prior-year tax (110% over $150,000 AGI) or 90% of current-year tax, no penalty applies even if your payments are uneven. But you must actually make the payments by each quarterly deadline to qualify.

Track the Deadlines Accurately

The quarterly deadlines don't align with calendar quarters (Q2 covers April-May, not April-June), which trips people up. The Quarter Calculator helps you see which quarter you're in and when the next tax deadline falls. For counting business days until each payment deadline, use the Days Until Calculator.

The practical move: set calendar reminders for each quarterly deadline one week in advance, calculate your payment based on that quarter's earnings, and pay via the IRS Electronic Federal Tax Payment System (EFTPS). Paying a few days early costs nothing; paying a day late triggers penalties that compound daily.

Authoritative References

Quarterly estimated tax deadlines follow federal law (IRC §6654). This guide is informational only, not tax advice. Confirm dates and rules at the IRS website (irs.gov) and on Form 1040-ES. Talk to a tax professional about your payments.