Is There a Fee for a Tax Extension? Penalties and Interest

There is no fee for a tax extension. The IRS processes Form 4868 for free, the six-month extension is automatic, and you don’t have to explain why you need the time.¹ The catch is what the extension doesn’t do: it moves your filing deadline from April 15 to October 15, but it does not move your payment deadline. If you owe taxes and don’t pay by April 15, penalties and interest start the next day.

Where Costs Can Show Up Anyway

The government charges nothing, but a few paths to the extension involve outside fees.

Tax software and paid preparers often charge somewhere between $20 and $100 to submit an extension for you. You can avoid that by filing Form 4868 yourself through IRS Free File or by making an extension payment through IRS Direct Pay, both at no cost.²

If you pay any balance owed by credit or debit card, the IRS-authorized processors add convenience fees. Pay1040 charges 1.75% for credit cards and ACI Payments charges 1.85%.³ On a $5,000 payment that’s roughly $87 to $93 added to the bill. Paying directly from a bank account through IRS Direct Pay costs nothing.

Businesses use Form 7004 instead of 4868, and the IRS charges nothing for that six-month extension either.⁴

How to Get the Extension for Free

The fastest free option is making a payment through IRS Direct Pay and choosing “Extension” as the payment reason. The IRS treats that as your extension request without a separate form, and it works even if you’re only paying part of what you owe.²

You can also file Form 4868 electronically through IRS Free File, or mail a paper copy of the form to the IRS service center for your region.⁵ If you mail it, the postmark date is what counts, so April 15 in the mail is on time even if the IRS receives it later. Certified mail with a return receipt gives you proof.

Form 4868 asks for basic identifying information and an estimate of your tax liability, what you’ve already paid in, and the balance owed. The IRS wants a reasonable, good-faith estimate. A rough number built from your prior return and current W-2s and 1099s is fine; deliberately understating the number to avoid paying is not.¹

What It Costs If You Owe and Don’t Pay by April 15

Two charges start running the day after April 15 on any unpaid balance, extension or no extension.

Failure-to-Pay Penalty

The IRS charges 0.5% of the unpaid amount for each month, or part of a month, that the balance sits unpaid. The penalty maxes out at 25% of the tax owed.⁶ On a $10,000 balance that’s $50 a month before interest.

The rate is cut in half, to 0.25% per month, if you file on time (an extension counts) and have an installment agreement in place with the IRS.⁷

Interest

Interest runs on the unpaid balance from April 15 until the debt is cleared. The rate adjusts every quarter. For the second quarter of 2026, the individual underpayment rate is 6% annually.⁸ Interest also accrues on the penalties themselves, and unlike the penalty, it has no cap.

The Bigger Penalty the Extension Actually Avoids

The reason to file an extension even when you can’t pay is that the failure-to-file penalty is ten times steeper than the failure-to-pay penalty. It’s 5% of the unpaid tax per month, or part of a month, up to a 25% cap.⁹

If a return ends up more than 60 days late, there’s a minimum failure-to-file penalty of $525 or 100% of the unpaid tax, whichever is less, for returns due after December 31, 2025.⁹ Even for a modest balance, skipping the free extension and filing months late can add hundreds in penalties that filing Form 4868 would have prevented.

When both penalties apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount, so the combined bite is 5% per month (4.5% plus 0.5%) rather than 5.5%. After five months, the failure-to-file portion hits its 25% cap, but the failure-to-pay penalty keeps running.⁹

Ways to Reduce Penalties You’ve Already Been Charged

If penalties do land on you, a few programs can knock them down.

First-Time Abatement

If you filed everything required for the past three tax years and had no penalties assessed in that window, you can ask the IRS to waive failure-to-file and failure-to-pay penalties under its first-time abatement policy.¹⁰ You can request it by phone or in a written letter. It’s one of the more underused options for taxpayers with an otherwise clean record.

Reasonable Cause

The IRS can waive penalties for taxpayers who exercised ordinary care but still couldn’t file or pay on time. Serious illness, a death in the family, a natural disaster, or an inability to get records can qualify. Not knowing the rules, simply being short on money, or blaming a preparer generally will not.¹¹

Installment Agreements

If you can’t pay in full, a payment plan stops the situation from escalating to liens or levies. Individuals owing $50,000 or less in combined tax, penalties, and interest can apply online. Short-term plans of 180 days or less have no setup fee. Long-term plans with direct debit cost $22 to set up online; other payment methods cost $69 online. Low-income taxpayers may qualify for fee waivers.¹² Having the agreement in place while your return is filed on time also drops the monthly failure-to-pay rate from 0.5% to 0.25%.

State Extensions Are a Separate Question

Most states with an income tax offer their own automatic extension, often on the same six-month timeline. Some accept the federal extension automatically; others require a state form. As with the federal version, a state extension generally doesn’t extend your time to pay, so state late-payment penalties and interest can still apply. A few states reduce or waive the late-payment penalty if you’ve paid at least 90% of your state liability by the original due date. Check your state tax agency for the specifics.

Automatic Extra Time for Certain Taxpayers

Some taxpayers get more time without filing anything. U.S. citizens and resident aliens living abroad with their main place of business outside the country get an automatic two-month extension to June 15, claimed by attaching a statement to the return; Form 4868 on top of that gets the full October 15 extension. Interest on unpaid tax still runs from April 15.¹³

Service members in a designated combat zone get deadlines extended for their full time in the zone plus 180 days, with no interest or penalties during that period; the relief also covers a spouse.¹⁴ And when FEMA declares a major disaster, the IRS automatically postpones filing and payment deadlines for taxpayers in the affected area, with the specific dates set for each declaration.¹⁵

1
Internal Revenue Service. Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return
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Internal Revenue Service. Types of Payments Available to Individuals Through Direct Pay
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Internal Revenue Service. Pay Your Taxes by Debit or Credit Card or Digital Wallet
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Internal Revenue Service. About Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns
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Internal Revenue Service. About Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return
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Internal Revenue Service. Failure to Pay Penalty
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Office of the Law Revision Counsel. 26 U.S. Code 6651 – Failure to File Tax Return or to Pay Tax
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Internal Revenue Service. Internal Revenue Bulletin 2026-08
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Internal Revenue Service. Failure to File Penalty
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Internal Revenue Service. 20.1.1 Introduction and Penalty Relief
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Internal Revenue Service. Penalty Relief for Reasonable Cause
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Internal Revenue Service. Payment Plans; Installment Agreements
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Internal Revenue Service. U.S. Citizens and Resident Aliens Abroad – Automatic 2-Month Extension of Time to File
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Internal Revenue Service. Extension of Deadlines – Combat Zone Service
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Internal Revenue Service. IRS Announces Tax Relief for Taxpayers Impacted by Severe Winter Storms in the State of Louisiana