The penalty for paying taxes late is 0.5% of your unpaid federal tax balance for each month or partial month the money remains unpaid after the deadline, plus interest that compounds daily at a rate the IRS resets every quarter (7% annually as of early 2026). The penalty stops growing once it reaches 25% of the original balance, but interest keeps running until you pay in full. The total damage depends on how much you owe, how long you wait, and whether you also filed your return late.
How the Failure-to-Pay Penalty Works
The rule sits in 26 U.S.C. § 6651(a)(2). For each month or partial month your balance is late, the IRS adds 0.5% of the unpaid tax.1Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax On a $10,000 balance, that’s $50 the first month, $100 by the end of the second, and so on. The penalty keeps accruing until it reaches 25% of the original amount owed.
A filing extension does not extend the payment deadline. Pushing your return to October leaves the April 15 payment deadline in place. There is one narrow cushion: if you paid at least 90% of the tax shown on your return by April 15 and pay the rest when you file the extended return, the IRS generally treats that as reasonable cause and won’t charge the failure-to-pay penalty for the extension period.2Internal Revenue Service. 20.1.2 Failure To File/Failure To Pay Penalties
The rate can also double. If the IRS issues a notice of intent to levy your property and you don’t pay within 10 days, the monthly penalty rises to 1%.1Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax By that point the IRS has already sent multiple notices, so the jump isn’t a surprise, but ignoring collection letters is one of the most expensive things you can do.
Interest on Top of the Penalty
Interest starts the day after the deadline and runs until the balance hits zero. Unlike the monthly penalty, interest compounds daily.3Office of the Law Revision Counsel. 26 USC 6601 – Interest on Underpayment, Nonpayment, or Extensions of Time for Payment, of Tax The rate is the federal short-term rate plus three percentage points, reset each quarter.4Office of the Law Revision Counsel. 26 USC 6621 – Determination of Rate of Interest For the first quarter of 2026, the individual underpayment rate is 7%.5Internal Revenue Service. Revenue Ruling 2025-22 – Section 6621 Determination of Rate of Interest
Two features make interest sting more than people expect. It’s calculated on your full outstanding balance, which includes penalties already assessed, so you end up paying interest on your penalties, not just on the tax itself. And the IRS almost never waives interest, even when it agrees to remove penalties. Successfully getting a penalty abated still leaves you owing interest on the underlying tax for the entire period it was unpaid.6Internal Revenue Service. Penalty Relief for Reasonable Cause
Why Filing Late Is Much Worse Than Paying Late
If you can’t pay, file anyway. The failure-to-file penalty under 26 U.S.C. § 6651(a)(1) is 5% of your unpaid tax for each month the return is overdue, capped at 25%.7Internal Revenue Service. Failure to File Penalty That’s ten times the monthly rate for simply paying late. A $8,000 balance filed three months late picks up $1,200 in filing penalties alone, before the payment penalty and interest.
A minimum penalty kicks in once your return is more than 60 days overdue. For returns due in 2026, that minimum is the lesser of $525 or 100% of the unpaid tax.7Internal Revenue Service. Failure to File Penalty A small balance can generate a disproportionately large charge if you let two months pass without filing.
When both penalties apply, they don’t fully stack. For any month both are running, the 5% filing penalty is reduced by the 0.5% payment penalty, so the combined rate is 5% rather than 5.5%.1Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax The filing penalty maxes out after five months at 22.5%. The payment penalty keeps running afterward at 0.5% per month until it hits its own 25% cap. The maximum combined penalty exposure is 47.5% of the original tax, before interest.7Internal Revenue Service. Failure to File Penalty
How a Payment Plan Cuts the Penalty in Half
Setting up an IRS payment plan doesn’t erase the failure-to-pay penalty, but it halves the rate. If you filed on time and have an approved installment agreement, the monthly penalty drops from 0.5% to 0.25%.8Internal Revenue Service. Failure to Pay Penalty Over a long repayment period, that adds up.
The IRS offers two structures:
- A short-term plan covers balances paid within 180 days. There’s no setup fee. Interest and the reduced penalty still accrue.
- A long-term installment agreement uses monthly payments. Setup fees range from $22 to $178 depending on whether you apply online or by phone and whether you authorize automatic bank withdrawals. The cheapest option is a direct debit agreement set up online at $22. Taxpayers at or below 250% of the federal poverty level can have the fee waived entirely for direct debit agreements.9Internal Revenue Service. Payment Plans – Installment Agreements
An Offer in Compromise is a separate path in which the IRS agrees to accept less than the full amount owed. If accepted, interest stops accumulating on the accepted offer amount from the date of acceptance. Default on the terms and all original penalties and interest are reinstated.10Internal Revenue Service. Offer in Compromise – Frequently Asked Questions
Getting the Penalty Removed
The IRS can remove late-payment and late-filing penalties under two main programs. Neither erases interest, which keeps running.
First-Time Abatement
If your compliance history is clean, the IRS will usually waive the penalty without requiring proof of hardship. You need to have filed all required returns for the three tax years before the penalty year and have no penalties during that same three-year window (or any prior penalty was removed for a reason other than First-Time Abatement).11Internal Revenue Service. Administrative Penalty Relief You can request it by calling the IRS or writing a letter. No special form is required.
Reasonable Cause
If First-Time Abatement isn’t available, you can still ask for relief by showing you exercised ordinary care but couldn’t comply due to circumstances beyond your control. The IRS evaluates these case by case. Situations that tend to succeed include serious illness, natural disasters, inability to obtain records, and IRS system issues that delayed an electronic filing or payment.6Internal Revenue Service. Penalty Relief for Reasonable Cause
What generally doesn’t work: not having the money, not knowing the deadline, or blaming a tax preparer. The IRS holds you responsible for meeting deadlines even if you hired someone.6Internal Revenue Service. Penalty Relief for Reasonable Cause For a formal written request, you can file Form 843 with documentation explaining the circumstances.12Internal Revenue Service. Instructions for Form 843 – Claim for Refund and Request for Abatement
When a Payment Bounces
A payment that fails creates its own charge. Under 26 U.S.C. § 6657, a dishonored payment of $1,250 or more triggers a penalty of 2% of the payment amount. A rejected $5,000 check adds $100 on top of the underlying balance. For payments under $1,250, the penalty is the lesser of $25 or the payment amount itself.13Office of the Law Revision Counsel. 26 USC 6657 – Bad Checks The rule applies to electronic payments as well as paper checks and can be waived if you can show you had reasonable cause to believe the payment would clear.
The larger cost of a bounced payment isn’t the 2%. It’s that your tax remains unpaid, so the failure-to-pay penalty and daily interest keep running as if you had never paid at all.