If your income arrives without tax taken out of it — freelance work, a business, rent, a large capital gain, a pension with no withholding — the government expects to be paid during the year, not in one lump the following April. Estimated tax payments are how you do that. Here is how to size them, when they are due, and how to never owe the penalty.
Who has to pay estimated tax
The 2026 Form 1040-ES states the test in two parts. You must pay estimated tax for 2026 if both are true:
- You expect to owe at least $1,000 in tax for 2026 after subtracting your withholding and refundable credits; and
- You expect your withholding plus refundable credits to be less than the smaller of 90% of your 2026 tax or 100% of the tax shown on your 2025 return.
A refundable credit pays you money even when your tax is already zero — the earned income credit and the refundable child tax credit are the common ones. Both conditions must be met: a driver with $9,000 of gig income whose spouse's withholding already covers the household bill fails part two and owes nothing.
The clean exemption. You owe no estimated tax for 2026 at all — however large this year's bill — if you had no tax liability for 2025, were a U.S. citizen or resident alien all year, and your 2025 tax year covered a full 12 months.
Farmers and fishers with at least two-thirds of gross income from those sources substitute 66⅔% for 90%, and may instead pay everything by January 15, 2027. Corporations use a $500 threshold.
The four payment periods are not even quarters
Everyone calls these quarterly payments. They are not quarters. The periods run three, two, three and four months, so the first two land 61 days apart.
| Installment | Income earned during | Payment due |
|---|---|---|
| 1st | January 1 – March 31, 2026 | Wednesday, April 15, 2026 |
| 2nd | April 1 – May 31, 2026 | Monday, June 15, 2026 |
| 3rd | June 1 – August 31, 2026 | Tuesday, September 15, 2026 |
| 4th | September 1 – December 31, 2026 | Friday, January 15, 2027 |
Form 1040-ES adds an escape hatch: skip the January 15, 2027 payment entirely if you file your 2026 return by February 1, 2027 and pay the whole balance with it.
For tax year 2027: April 15, 2027; June 15, 2027; September 15, 2027; and January 18, 2028 — pushed from Saturday January 15 past Martin Luther King Jr. Day on Monday January 17.
April 15, 2027 is not moved. District of Columbia Emancipation Day falls on Friday, April 16, 2027 — the day after the Thursday due date — so the postponement rule does not apply. Do not plan on an extra weekend.
The three safe harbors, precisely
A safe harbor is a payment total that makes you penalty-proof even if you guessed your income badly. You need only the smaller of the pair that applies.
- 90% of your 2026 tax
- Accurate, but unknowable until the year is over.
- 100% of your 2025 tax
- The full tax shown on your 2025 return, split across the four installments. That return must cover all 12 months.
- 110% of your 2025 tax
- If your 2025 adjusted gross income exceeded $150,000 ($75,000 if you file 2026 as married filing separately), the prior-year test rises to 110%. Farmers and fishers are exempt.
The prior-year harbor is the one most people should use, because it is the only one built on a number you already have. Your 2025 total tax is printed on your filed return; divide by four, pay that on each date, and the penalty cannot reach you no matter what 2026 does. Chase the 90% target and you are betting a penalty on a forecast made in April about December.
It is the wrong choice when income dropped sharply, since paying last year's tax then lends the Treasury money for a year. Note the limit too: it prevents the penalty, not the balance due next April.
A worked example: a freelancer earning $85,000
Single, no dependents, $85,000 of net profit on Schedule C for 2026, no other income, standard deduction.
| Step | Calculation | Amount |
|---|---|---|
| Net profit from self-employment | Schedule C, line 31 | $85,000.00 |
| Net earnings subject to SE tax | $85,000 × 92.35% | $78,497.50 |
| Social Security portion | $78,497.50 × 12.4% | $9,733.69 |
| Medicare portion | $78,497.50 × 2.9% | $2,276.43 |
| Self-employment tax | sum of the two above | $12,010 |
| Deduction for one-half of SE tax | $12,010 ÷ 2 | $6,005 |
| Adjusted gross income | $85,000 − $6,005 | $78,995 |
| Standard deduction, single, 2026 | Rev. Proc. 2025-32 | $16,100 |
| Taxable income before QBI deduction | $78,995 − $16,100 | $62,895 |
| Qualified business income deduction | lesser of 20% × $78,995 ($15,799) or 20% × $62,895 | $12,579 |
| Taxable income | $62,895 − $12,579 | $50,316 |
| Income tax | $1,240 + 12% × ($50,316 − $12,400) | $5,790 |
| Total 2026 tax | $5,790 income tax + $12,010 SE tax | $17,800 |
The full 12.4% Social Security piece applies because $78,497.50 sits below the 2026 wage base of $184,500. Medicare's 2.9% has no ceiling. The additional 0.9% Medicare tax starts at $200,000 single and $250,000 married filing jointly, so it does not bite here.
Ninety percent of $17,800 is $16,020, or $4,005 per installment. If the 2025 return showed total tax of $14,000, the prior-year harbor is smaller — $3,500 per installment — and safer, because it cannot move. Pay $3,500 four times, set the difference aside, settle the rest in April.
Why the QBI deduction is $12,579, not $15,799. The Section 199A deduction is capped at 20% of taxable income figured before the deduction itself, less net capital gain. That cap is the lower figure here, so it wins — miss the step and every installment comes out too small.
The withholding trick that fixes an underpayment after the fact
Estimated payments are credited on the day you make them. Withholding is different. The Form 2210 instructions are explicit: for withheld federal income tax, "you are considered to have paid one-fourth of these amounts on each payment due date unless you can show otherwise." A dollar withheld in December counts as 25 cents paid on each of the four due dates. It is the only backdating the rules allow.
Worked example. A couple files jointly; the freelancing spouse missed the April and June installments and is about $8,000 short. In early November the other spouse files a new Form W-4 asking for $8,000 of extra withholding across the remaining paychecks. That $8,000 is deemed paid $2,000 on each due date, so the April and June shortfalls are filled retroactively and the penalty on them disappears.
The same lever works through Form W-4P for pensions and Form W-4R for IRA distributions. Two limits: the employer must be able to withhold that much before December 31, and the cash still has to come from somewhere. The IRS Tax Withholding Estimator will size the change.
The annualized income installment method
The default rule assumes income arrives in an even stream, which is why four equal payments work. When income is lumpy, Schedule AI of Form 2210 matches each installment to what you had earned by that point.
It runs on cumulative periods: January 1 – March 31, January 1 – May 31, January 1 – August 31, and the full year. Income in each is annualized by multiplying by 4, 2.4, 1.5 and 1, and the required cumulative payment is 22.5%, 45%, 67.5% and 90% of the annualized tax.
It earns its keep when a large share of income arrived late — a business sold in November, a December capital gain, a seasonal operation. It does not when the prior-year harbor is available and affordable. The cost is real: Form 2210 with Schedule AI must be filed even when no penalty is owed, on records good enough to defend each period.
How to actually pay
- IRS Online Account — pay and see your full payment history in one place. Best option: you can verify the money landed on the right year.
- IRS Direct Pay — free transfers from checking or savings, no enrollment. Choose reason "Estimated Tax," Form 1040-ES, tax year 2026.
- EFTPS — free, but enroll first and wait for a PIN by mail. Worth it for one feature: schedule all four payments a year ahead.
- Card or digital wallet — via IRS.gov/payments. Processors charge a fee; the IRS does not.
- Form 1040-ES vouchers by mail — one per due date. Check payable to "United States Treasury," marked "2026 Form 1040-ES" with your Social Security number. A U.S. postmark by the due date counts as timely.
You are not limited to four payments. Monthly is fine, provided the cumulative total by each due date meets that period's amount.
The most expensive two seconds in the process is the tax-year dropdown. A payment applied to 2025 instead of 2026 sits as an overpayment on a closed year while 2026 accrues interest as though nothing was paid.
State estimated taxes are a separate problem
Nine states impose no individual income tax on wages or self-employment income: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington and Wyoming. New Hampshire's interest and dividends tax was repealed for tax periods beginning after December 31, 2024; Washington taxes certain long-term capital gains but not ordinary income.
Everywhere else runs its own system, with its own threshold, forms, portal and arithmetic. California shows how far a state can diverge. Payments are required if you expect to owe $500 or more ($250 filing separately). The harbors are 90% of the current year or 100% of the prior year, rising to 110% where prior-year California AGI exceeded $150,000, and anyone with current-year California AGI of $1,000,000 or more loses the prior-year harbor entirely. Most striking, the installments are unequal — 30% due April 15, 40% on June 15, nothing on September 15, and 30% on January 15. Send Sacramento a quarter each time and you are underpaid all year.
What the penalty actually costs
It is not a flat fine. It is interest, charged on each shortfall for every day it stays unpaid, at a rate the IRS resets quarterly. For July 1 through September 30, 2026 the non-corporate underpayment rate is 7%. The rate for the quarter beginning October 1, 2026 had not been published when this was written; the IRS normally announces it in early September, and current figures sit on the IRS quarterly interest rates page.
At 7%, the rule of thumb is roughly $17 per $1,000 left unpaid for 90 days ($1,000 × 7% × 90 ÷ 365 = $17.26).
Worked example. Our freelancer skips the $4,005 installment due September 15, 2026 and pays it with the return on April 15, 2027 — 212 days late. At 7% that is $4,005 × 7% × 212 ÷ 365 = about $163. The real charge will differ slightly, since the rate resets quarterly and later quarters are unpublished, but that is the order of magnitude.
The IRS calculates the penalty and bills you, so most people never file Form 2210 — you file it to use the annualized method or request a waiver. Waivers exist for a casualty, disaster or other unusual circumstance, and for people who retired after reaching age 62 or became disabled, where the underpayment was due to reasonable cause and not willful neglect. The penalty is not deductible.
The most common mistakes
- Budgeting for income tax and forgetting self-employment tax. Above, SE tax of $12,010 was more than double the income tax.
- Aiming at 90% of the current year when the prior-year figure is fixed and knowable — then applying the payment to the wrong tax year.
- Skipping the January installment because April feels close enough. Interest runs from January 15 unless you file and pay in full by February 1, 2027.
- Overlooking the QBI deduction and overpaying all year.
- Assuming income is untaxed because no Form 1099-K arrived. For 2025 and 2026 a third-party settlement organization reports only above $20,000 gross and 200 transactions. The income is taxable either way.
- Paying the federal estimate and forgetting the state one.
- Never recalculating. A new job with withholding, a spouse's income change, a doubled business — each invalidates the January schedule.
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Key takeaways
- The trigger is $1,000 owed after withholding and refundable credits, plus withholding that falls short of the safe harbor. No tax liability at all in 2025? You owe no estimates for 2026.
- Use the prior-year safe harbor. 100% of your 2025 tax — 110% if 2025 AGI topped $150,000 ($75,000 married filing separately) — is a fixed number that makes the penalty impossible. A 90% forecast is not.
- The 2026 dates are April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027, covering periods three, two, three and four months long — not even quarters.
- Self-employment tax usually dominates. At $85,000 of net profit it is $12,010 against $5,790 of income tax, and the QBI deduction cuts only the income tax side.
- Withholding backdates itself. Tax withheld at any point counts as one-fourth paid on each due date, so a late-year Form W-4 change repairs an earlier shortfall.
- The penalty is interest, currently 7% for non-corporate underpayments in the quarter ending September 30, 2026 — about $17 per $1,000 per 90 days. Entirely avoidable.
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