The 2026 calendar
These are the federal dates for individuals and pass-through business owners. When a deadline lands on a weekend or federal holiday, it shifts to the next business day.
Final estimated-tax installment for the 2025 tax year (Form 1040-ES).
Tax Day. File your 2025 return (or request an extension), pay any 2025 balance due, and make the 1st 2026 estimated payment — all on the same date.
Second estimated-tax installment for the 2026 tax year.
Third estimated-tax installment for the 2026 tax year.
Final deadline to file a 2025 return that was on extension. An extension extends filing, not payment — interest and late-payment penalties still run from April 15.
Final estimated-tax installment for the 2026 tax year.
An extension moves your filing deadline to October 15 — it does not move your payment deadline. Tax not paid by April 15 accrues interest and the failure-to-pay penalty regardless. If you can't pay, file (or extend) anyway to avoid the much larger failure-to-file penalty, and pay what you can.
Miss one? Size the penalty, then remove it
Each missed deadline maps to a specific penalty — and each is frequently reduced or removed:
- Filed late: the failure-to-file penalty (5%/month).
- Paid late: the failure-to-pay penalty (0.5%/month) plus interest.
- Underpaid estimates: the underpayment penalty — check your safe harbor before it applies.
If you already paid a penalty, the refund estimator shows what abatement could recover.