Q4 Estimated Tax: What to Pay by January 15, 2027
The fourth installment for 2026 is due January 15, 2027 (Form 1040-ES). It covers income from September through December — and it's your last chance to catch up on earlier quarters before the penalty keeps adding up.
The amount
- Work out the required annual payment: the smaller of 90% of your 2026 tax or 100% of your 2025 tax (110% if your 2025 AGI was over $150,000).
- Subtract every 2026 estimated payment you've made — but not the January 2026 payment, which was for 2025 — and your withholding.
- What's left is the amount that reaches the safe harbor. Paying it by January 15 stops the penalty on the fourth installment; earlier shortfalls are charged only for the days they were late.
Or file early
You don't have to make the January payment if you file your 2026 return and pay all the tax by February 1, 2027.
How to pay
IRS Direct Pay or EFTPS — choose "Estimated tax" and tax year 2026.
Last reviewed 2026-10-28. General information, not tax advice. Your tax adviser can tell you what applies to you.