Overview
- The IRS deadline for the third quarterly estimated tax payment applies to taxpayers who did not have enough federal withholding and must be met Tuesday, September 15, 2026 to avoid underpayment penalties.
- Those most likely to owe include self-employed workers, small‑business owners and people with investment or other income that lacks withholding.
- Taxpayers can calculate and pay using Form 1040‑ES or pay online through IRS Direct Pay, the IRS portal, EFTPS, or by card or check with a payment voucher; Direct Pay and EFTPS are free from bank-account fees.
- The same calendar date also requires employer payroll deposits in some cases and is the deadline for certain business filings and deposits for entities that requested six‑month extensions.
- After this deadline the next scheduled estimated payment date is January 15, 2027, and taxpayers who filed an extension should remember that an extended filing date does not extend the payment date and unpaid balances accrue interest and penalties.