What Happens If You Don’t Pay Quarterly Taxes on Time?

If you don’t pay quarterly taxes on time, the IRS charges an underpayment penalty that functions like daily interest on the amount you should have paid, running from the missed deadline until you pay or until your annual return is due, whichever comes first. The penalty applies even if you end up owed a refund, and it’s calculated quarter by quarter, so a shortfall in April isn’t erased by overpaying in September. The faster you pay, the smaller the bill.

How the Penalty Works

The underpayment penalty isn’t a flat fee. It’s interest on the shortfall, compounded daily from each quarterly deadline.¹ The IRS treats each quarter separately, which is the detail that catches people out. If you earned freelance income in the spring and didn’t pay anything on it until January, you still owe a penalty on the spring quarter, regardless of whether your total payments eventually covered your full annual tax.

If you leave the penalty itself unpaid after it’s assessed, interest accrues on top of it, along with any underlying tax balance, until everything is settled.²

What It Actually Costs

The rate isn’t fixed. The IRS resets it each quarter based on the federal short-term rate. For Q1 2026, the underpayment rate is 7% per year, compounded daily.³ It drops to 6% for Q2 2026.⁴

A worked example makes the scale clearer. Suppose you owed a $5,000 quarterly installment and paid nothing by the April 15 deadline. At a 7% annual rate, that’s about $0.96 a day. Sixty days late comes to roughly $58. One missed quarter won’t ruin you, but the amounts stack across quarters, and across years for anyone who makes a habit of underpaying.

The IRS figures the actual amount on Form 2210. Three variables drive it: how much you underpaid each quarter, how long the underpayment lasted, and the interest rate in effect during that period.⁵

Pay Now to Stop the Clock

Because the penalty accrues daily, paying as soon as you realize you’ve missed a deadline is the single most effective move. A payment that lands a week late costs far less than one that lands three months late.

The IRS offers a few ways to pay:

IRS Direct Pay, a free bank transfer from a checking or savings account, with no enrollment required.
IRS Online Account, which also lets you see your balance and payment history in one place.
A check or money order mailed with a Form 1040-ES voucher to the address in the form instructions.

One change to be aware of if you’re setting up a payment method now: as of October 2025, the Electronic Federal Tax Payment System no longer accepts new enrollments from individual taxpayers, and the IRS plans to move all individuals to Direct Pay or IRS Online Account by late 2026.⁶ For first-time setup, go with Direct Pay.

You May Not Owe a Penalty At All

The underpayment penalty is measured against your full-year numbers when you file. Missing a deadline doesn’t automatically lock in a penalty if your total year-end payments meet one of these safe harbors:⁷¹

Your total tax after withholding and credits comes in under $1,000.
Your estimated payments and withholding cover at least 90% of this year’s tax.
Your payments and withholding cover at least 100% of last year’s tax (110% if your prior-year adjusted gross income exceeded $150,000, or $75,000 if married filing separately).
You had zero tax liability the prior year, were a U.S. citizen or resident the whole year, and that year covered 12 months.

The prior-year rule is the one most freelancers lean on because it removes the guesswork. Divide last year’s tax by four, pay that each quarter, and the penalty can’t touch you no matter what this year’s income does.

Two Ways to Fix a Miss Before Year-End

Add Withholding From a Paycheck

If you also have wage income, federal tax withheld from wages is treated as if it were paid evenly throughout the year, even when it was actually withheld in a single quarter.⁸ Increasing your W-4 withholding late in the year can retroactively cover earlier quarters for penalty purposes. Someone who realizes in October that they’ve underpaid can sometimes close the gap this way without sending a separate payment to the IRS.

Use the Annualized Income Method

If your income arrived unevenly, the annualized income installment method lets you base each quarter’s required payment on what you actually earned during that period rather than assuming a flat 25% split. For seasonal work, lumpy commissions, or back-loaded income, this can eliminate the penalty for quarters when your income was genuinely low. You complete Schedule AI on Form 2210 when you file.⁵

When the IRS Will Waive the Penalty

The estimated tax penalty is harder to get waived than other IRS penalties, and the common waiver routes don’t apply.

What Doesn’t Work

General reasonable cause arguments won’t remove it. The IRS has stated that the underpayment penalty “generally cannot be waived due to reasonable cause.”⁷

First-Time Penalty Abatement doesn’t apply either. That administrative waiver covers failure-to-file, failure-to-pay, and failure-to-deposit penalties only; the Internal Revenue Manual explicitly excludes estimated tax penalties from FTA eligibility.⁹ Advice to request FTA for an estimated tax penalty is wrong.

What Can Work

Two narrow situations give the IRS discretion to waive the penalty:¹

A casualty, disaster, or other unusual circumstance made imposing the penalty inequitable. For federally declared disaster areas, the IRS typically postpones quarterly deadlines and waives penalties for affected taxpayers automatically.¹⁰
You retired after reaching age 62 or became disabled during the tax year or the year before, and the underpayment was due to reasonable cause rather than neglect.

Both waivers are requested on Form 2210 at filing. Check the applicable box in Part II and attach an explanation.

Don’t Forget State Deadlines

Most states with an income tax impose their own estimated tax requirements and underpayment penalties, separate from the federal system. Rates and rules vary widely, and some states set different due dates, so missing a federal deadline doesn’t automatically mean you’ve missed the state one, or vice versa. If you owe federal estimated taxes, check whether your state requires them too.

1
Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax
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Internal Revenue Service. Interest
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Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026
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Internal Revenue Service. Internal Revenue Bulletin 2026-08
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Internal Revenue Service. Instructions for Form 2210 (2025)
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U.S. Department of the Treasury. Welcome to EFTPS Online
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Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
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Internal Revenue Service. Publication 505 (2025), Tax Withholding and Estimated Tax
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Internal Revenue Service. 20.1.1 Introduction and Penalty Relief
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Internal Revenue Service. IRS Reminder – Disaster Victims in Twelve States Have Automatic Extensions to File and Pay Their 2024 Taxes