Quarterly estimated tax ESTIMATE
Split a 2026 required annual payment into four equal installments. You supply the tax figures.
General information, not tax or legal advice. The 90%, 100%, 110%, and $1,000 rules below are the IRS descriptions linked on this page. Due dates are the IRS calendar-year schedule. This is not Form 2210.
Equal installment ESTIMATE
The smaller of two tests
The IRS estimated-tax page says most people avoid the underpayment penalty if they owe less than $1,000 after withholding and credits, or if they paid at least 90% of the current year’s tax, or 100% of the prior year’s tax, whichever is smaller. The IRS FAQ on individuals states that the prior-year percentage becomes 110% when prior-year adjusted gross income was greater than $150,000, or $75,000 if married filing separately. Farmers, fishers, and people who did not file a full prior-year return have special rules this form does not apply. Withholding is subtracted from the required annual amount, and the remainder is divided by four. That is the regular equal-installment idea, not the annualized-income method on Form 2210.
Example: expected tax $10,000, withholding $1,000, prior-year tax $8,000, prior AGI $100,000. Ninety percent is $9,000. The prior-year safe harbor is 100% × $8,000 = $8,000. The required payment is the smaller one, $8,000. After withholding, $7,000 remains, or $1,750 a quarter. If prior AGI were $200,000, the prior-year figure would be 110% × $8,000 = $8,800, and that would be the smaller of $9,000 and $8,800.
2026 due dates for calendar-year individuals
The IRS FAQ “When are quarterly estimated tax payments due?” gives these periods. For tax year 2026 they fall on weekdays, so the weekend rule does not move them. A legal holiday still could. Confirm Publication 509 if you are close to a date.
| Income period | Due date |
|---|---|
| January 1 – March 31, 2026 | April 15, 2026 |
| April 1 – May 31, 2026 | June 15, 2026 |
| June 1 – August 31, 2026 | September 15, 2026 |
| September 1 – December 31, 2026 | January 15, 2027 |
The IRS also says that if the due date is a Saturday, Sunday, or legal holiday, the payment is on time on the next business day. Paying the balance with a return filed by January 31 can replace the January estimated payment in the situation described in Publication 505. Fiscal-year filers use a different calendar. Self-employment tax from the self-employment estimator is part of “expected total tax” only after you add income tax and subtract credits yourself.
Sources
- IRS, Estimated taxes — under $1,000, 90% of current-year tax, or 100% of prior-year tax.
- IRS FAQ, estimated tax for individuals — 110% when prior AGI was over $150,000 ($75,000 if married filing separately).
- IRS FAQ, when estimated tax payments are due — April 15, June 15, September 15, and January 15.
- IRS Publication 505 — withholding and estimated tax, including the January payment exception.