The 2026 Quarterly Estimated-Tax Deadline Is September 15 — Here's Who Owes

If you earn 1099 income, freelance revenue, or investment gains without automatic tax withholding, your third quarterly estimated tax payment for tax year 2026 is due to the IRS on September 15, 2026.

Who Needs to Make a Q3 Estimated Tax Payment?

Under IRS rules, individuals generally must make quarterly estimated payments if both of the following conditions apply:

• You expect to owe at least $1,000 in federal tax for 2026 after subtracting withholding and tax credits.
• You expect your withholding and refundable credits to be less than the smaller of:
  1. 90% of the tax to be shown on your 2026 tax return, or
  2. 100% of the tax shown on your 2025 tax return (110% if your 2025 AGI was over $150,000).

Understanding the 15.3% Self-Employment Tax Rate

Unlike W-2 employees whose employers cover half of Social Security and Medicare taxes, 1099 earners pay the full 15.3% self-employment tax on net earnings (92.35% of net profit). For 2026, the Social Security portion (12.4%) applies up to the wage base cap of $176,100.

How to Calculate Your Q3 Payment Amount

To calculate your exact payment, calculate your estimated net 1099 profit for the entire year, apply the 2026 standard deduction ($15,000 single / $30,000 married joint), compute your income tax bracket liability plus SE tax, and divide by 4.

You can use our interactive 2026 1099 Tax Estimator to get an instant calculation tailored to your specific income and business expense totals.