Form 2210, Underpayment of Estimated Tax by Individuals, Estates, and Trusts, works out whether you owe a penalty for not paying enough tax during the year. As of October 2026, you're generally safe if withholding and on-time estimated payments covered the smaller of 90% of this year's tax or 100% of last year's (110% if last year's AGI was over $150,000), and in most cases you don't file the form at all: the IRS figures the penalty and sends a bill.
That last point is worth knowing. The form exists mainly for the cases where you want to reduce the penalty, ask for a waiver or prove your income came late in the year. If none of those apply, leave the penalty line blank and let the IRS do the sum.
Who owes the underpayment penalty
Tax in the US is pay as you go. For the 2025 tax year, you may owe the penalty if your withholding and timely estimated payments didn't reach at least the smaller of:
- 90% of your 2025 tax, or
- 100% of your 2024 tax, provided your 2024 return covered 12 months.
| Situation | What changes |
|---|---|
| 2024 AGI over $150,000 ($75,000 married filing separately) | Use 110% of last year's tax instead of 100% |
| At least two-thirds of gross income from farming or fishing | A lower percentage replaces the 90% test, and Form 2210-F may apply |
| Tax on the return minus withholding is under $1,000 | No penalty and no Form 2210 |
| No tax liability for 2024, US citizen or resident all year, 12 month return | No penalty and no Form 2210 |
The quarterly due dates
| Payment | Covers income earned | Due |
|---|---|---|
| 1 | January 1 to March 31 | April 15 |
| 2 | April 1 to May 31 | June 15 |
| 3 | June 1 to August 31 | September 15 |
| 4 | September 1 to December 31 | January 15 of the next year |
The penalty is figured separately for each installment. So you can owe a penalty for the April payment even if you paid enough by January, and even if you end up with a refund. It's calculated on the underpaid amount, how long it was underpaid and the published quarterly interest rates for underpayments. Our estimated tax payments guide covers how to make the payments themselves.
When you must file Form 2210
Use the flowchart at the top of page 1. You must figure the penalty yourself and attach the form if you tick any of these boxes in Part II:
- Box B: you're asking for part of the penalty to be waived.
- Box C: you're using the annualized income installment method on Schedule AI.
- Box D: you're treating withholding as paid on the dates it was taken, rather than spread evenly through the year.
Box A, a request to waive the whole penalty, needs only page 1 attached. If you file your 2025 return by April 15, 2026 and let the IRS figure the penalty, there's no interest on that penalty as long as you pay by the date on the bill.
Ways to cut or remove the penalty
- Annualized income method: if most of your income arrived late in the year, Schedule AI matches each payment to the income you'd earned by that point.
- Actual withholding dates: if more tax was withheld early in the year, box D can help.
- Retirement or disability waiver: available if you retired after reaching age 62, or became disabled, in 2024 or 2025 and the underpayment was due to reasonable cause.
- Casualty, disaster or other unusual circumstance: attach a statement and documents such as police or insurance reports.
- Federally declared disasters: the IRS applies relief automatically by county, so generally don't file Form 2210 for that.
A penalty bill can sometimes be spread out, and our guide to IRS installment requests explains how to ask.
How the IRS works out the figure
The IRS bases the penalty on the tax shown on your original return, or on a later return filed on or before the due date. Tax shown means total tax minus total refundable credits. It then applies the published quarterly underpayment interest rates to each late or short installment for the number of days it was outstanding, and interest is charged on the penalty itself until it's paid. If you were penalized because you relied on incorrect written advice the IRS gave in response to your own written request, you can ask for an adjustment with a signed statement. Estates get some breathing room too: no penalty applies to a decedent's estate for any tax year ending before 2 years after the death.
The IRS page notes that the penalty generally can't be waived just for reasonable cause, outside those specific routes. A superseding return filed by the original due date counts as the original, which matters if you fix an error before the deadline.
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If you need more time to file, our guide to the tax filing extension form explains the extension.
The verdict
For a self-employed person, the simplest protection is the prior-year safe harbor: pay in at least 100% of last year's tax (110% above the $150,000 AGI line) across the four dates and the penalty can't apply. File Form 2210 only when it lowers the bill, usually because income came in lumpy, and keep the flowchart in front of you while you do it. If you're a sole proprietor, the profit on your Schedule C is what drives the payments.
Frequently asked questions
Must I file Form 2210 with my return?
Usually not. The IRS figures the penalty and sends a bill. You must file it only if you check box B, C or D in Part II, and box A needs page 1 attached.
What is the safe harbor for estimated tax?
Paying at least the smaller of 90% of this year's tax or 100% of last year's tax through withholding and timely estimates. The 100% becomes 110% if last year's AGI was over $150,000, or $75,000 for married filing separately.
Is there a minimum before the penalty applies?
Yes. If the tax on your return minus withholding is less than $1,000, you don't owe the penalty or need the form.
Can the underpayment penalty be waived?
Part or all of it can be waived if you retired after age 62 or became disabled with reasonable cause, or if a casualty, disaster or unusual circumstance made it unfair to impose.
Does a refund mean I won't owe the penalty?
No. The penalty is figured separately for each due date, so you can owe it for an early quarter even if you're due a refund.
