IRS Late Filing & Late Payment Penalty Calculator
Estimate IRS late-filing and late-payment penalties plus daily-compounded interest. Enter your unpaid tax and filing dates to see the total owed.
IRS Late Filing & Late Payment Penalty Calculator
Unpaid Federal Tax
The balance of tax you owe after withholding and credits. Penalties and interest are figured on this amount.
Key Dates
IRS Interest Rate
Annual rate, compounded daily. Equals the federal short-term rate plus 3 points and changes quarterly. Q1 2026 was 7%, Q2 2026 is 6%.
Fraudulent Failure to File
If the failure to file is fraudulent, the late-filing penalty rises to 15% per month, up to a 75% cap. Leave this off for an ordinary late return.
Estimate only, not tax or legal advice. Interest is figured on the unpaid tax principal at a single rate; the IRS resets the rate each quarter and also charges interest on penalties, so your actual figure may differ. Download Tax47 for a full picture of what you owe.
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How IRS late-filing and late-payment penalties work
The IRS charges two separate penalties when a return is late or a balance goes unpaid. The failure-to-file penalty (IRC 6651(a)(1)) is 5% of your unpaid tax for each month or part of a month the return is late. The failure-to-pay penalty (IRC 6651(a)(2)) is 0.5% of your unpaid tax for each month or part of a month the tax stays unpaid. Both treat a partial month as a full month, so even one day into a new month adds another month of penalty.
Each penalty stops at its own 25% cap. The failure-to-file penalty hits that cap after five months (5% times 5). The failure-to-pay penalty grows much more slowly and would take 50 months to reach 25%. Because the late-filing penalty is ten times larger per month, filing on time matters even when you can't pay the full balance.
When both penalties apply (the combined-penalty rule)
For any month where both penalties apply, the failure-to-file rate is reduced by the failure-to-pay rate. So instead of 5% plus 0.5%, you pay 4.5% (filing) plus 0.5% (payment) for a combined 5% that month. Over the first five months the late-filing penalty therefore caps at about 22.5% rather than the full 25% when the late-payment penalty runs the whole time.
There is also a minimum penalty for returns filed more than 60 days late. In that case the failure-to-file penalty is at least the lesser of $525 (for returns required to be filed in 2026) or 100% of the tax shown on the return. You pay the greater of this minimum or the standard percentage. For example, a $5,000 balance filed and paid five months late picks up 22.5% in failure-to-file penalty ($1,125) plus 2.5% in failure-to-pay penalty ($125), for $1,250 in penalties before interest.
How IRS interest is calculated on unpaid taxes
On top of penalties, the IRS charges interest on unpaid tax under IRC 6601 and 6621. For individual taxpayers the rate equals the federal short-term rate plus 3 percentage points, and it compounds daily. The rate resets every quarter, so a balance carried across quarters can accrue at more than one rate. For the first quarter of 2026 the rate was 7% per year, and for the second quarter it dropped to 6%.
This calculator applies a single rate that you can edit, compounding daily on the tax principal from the due date to the date paid (or to today if the balance is still open). The IRS also charges interest on assessed penalties, which this tool does not add, so treat the interest figure as a conservative estimate of the principal-only portion.
How to reduce or avoid IRS penalties
The single most effective step is to file on time, or file an extension, even if you can't pay. An extension removes the much larger failure-to-file penalty, though the failure-to-pay penalty and interest still run on the unpaid balance. Setting up an IRS payment plan can cut the failure-to-pay rate to 0.25% per month for taxpayers who filed on time.
If you already have penalties, you may qualify for first-time abatement when your prior three years are clean, or for reasonable-cause relief in situations such as serious illness, a death in the family, or a natural disaster. Paying down the balance as soon as you can also limits how much interest compounds. Estimates only. Not tax or legal advice. Consult a tax professional for your situation. Sources: IRS Failure to File Penalty, IRS Failure to Pay Penalty, IRS Quarterly Interest Rates, IRC 6651.
Frequently Asked Questions
Common questions about irs late filing & late payment penalty calculator
How much is the IRS penalty for filing taxes late?
The failure-to-file penalty is 5% of your unpaid tax for each month or part of a month your return is late, up to a maximum of 25%. A partial month counts as a full month, so a return one day into a new month gets charged for that whole month. The penalty stops growing after five months once it reaches the 25% cap.
What is the penalty for paying taxes late but filing on time?
The failure-to-pay penalty is 0.5% of your unpaid tax for each month or part of a month the tax stays unpaid, up to a maximum of 25%. It is much smaller than the late-filing penalty, which is why filing on time matters even when you can't pay the full balance right away.
What happens if both the late-filing and late-payment penalties apply in the same month?
For any month where both penalties apply, the failure-to-file rate is reduced by the failure-to-pay rate. The late-filing penalty drops to 4.5% and the late-payment penalty stays at 0.5%, for a combined 5% that month. The failure-to-file portion still caps at 25% (about 22.5% if the late-payment penalty ran the whole time), and the late-payment penalty continues up to its own 25% cap.
Is there a minimum penalty for filing more than 60 days late?
Yes. If your return is more than 60 days late, the minimum failure-to-file penalty is the lesser of $525 (for returns required to be filed in 2026) or 100% of the tax required to be shown on the return. You pay the greater of this minimum or the standard percentage-based penalty.
How does the IRS calculate interest on unpaid taxes?
Interest on unpaid tax is set at the federal short-term rate plus 3 percentage points for individual taxpayers, and it compounds daily. The rate resets every quarter, so a long-running balance can accrue interest at several different rates over time. Interest also applies to assessed penalties.
What is the current IRS interest rate for 2026?
For the first quarter of 2026 (January 1 to March 31) the rate for individuals was 7% per year. For the second quarter (April 1 to June 30) it dropped to 6% per year. Because the rate changes quarterly, this calculator lets you enter the rate that applies to your period and defaults to the latest published figure of 6%.
Does filing an extension stop the late-payment penalty?
No. An extension gives you more time to file your return, which avoids the failure-to-file penalty, but it does not extend the time to pay. The failure-to-pay penalty and interest still accrue on any unpaid tax from the original due date until you pay in full.
Can IRS penalties be removed or reduced?
Sometimes. The IRS offers first-time penalty abatement if you have a clean compliance history for the prior three years, and it grants reasonable-cause relief for circumstances such as serious illness or a natural disaster. Setting up a payment plan can also cut the failure-to-pay rate to 0.25% per month for taxpayers who filed on time.