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Quarterly Estimated Tax

Also called: quarterly tax, estimated tax payments, 1040-ES

Four annual prepayments of income tax made by self-employed and 1099 workers — Q1 Apr 15, Q2 Jun 15, Q3 Sep 15, Q4 Jan 15.

The U.S. tax system is pay-as-you-go. W-2 employees pay through paycheck withholding; self-employed and 1099 workers pay through four quarterly estimated payments using IRS Form 1040-ES.

You're required to pay estimated tax if you expect to owe at least $1,000 in tax for the year after withholdings. For most 1099 workers earning more than ~$8,000 of net SE income, this applies.

2026 deadlines:

  • Q1 — April 15, 2026 (income earned Jan 1 – Mar 31)
  • Q2 — June 15, 2026 (Apr 1 – May 31; only two months!)
  • Q3 — September 15, 2026 (Jun 1 – Aug 31)
  • Q4 — January 15, 2027 (Sep 1 – Dec 31)

Underpayment penalty: if you pay too little each quarter, the IRS charges interest at roughly short-term rates + 3%. The safe harbor: pay either 100% of last year's total tax (110% if AGI > $150K) or 90% of this year's projected tax, whichever is less. Meet that, no penalty.