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IRS Late Filing & Payment Penalty Calculator
Estimate what the IRS adds when a tax return is filed late, the tax is paid late, or both. Enter the unpaid tax and your dates to see the failure-to-file penalty, failure-to-pay penalty and interest, with a month-by-month schedule.
Last updated:
Tax and dates
$
Tax on the return minus withholding and payments made by the due date
Rates (editable)
% / year
Underpayment rate for individuals; changes quarterly
$
For returns over 60 days late: $525 for returns due in 2026, $510 in 2025
Enter your values to see the result.
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How to use the IRS Late Filing & Payment Penalty Calculator
Enter the unpaid tax: the balance due on your return after withholding and payments made by the due date.
Set the dates: original due date, the date you filed and the date you paid in full.
Tick extension or installment agreement if they apply.
Check the interest rate against the IRS's current quarterly rate.
Press Calculate penalties to see each penalty, the interest and the total to pay.
IRS penalty formulas
Failure to file = unpaid tax × 5% × months late (each partial month counts as a full month), maximum 25%.
Failure to pay = unpaid tax × 0.5% × months unpaid, maximum 25% (0.25% on an installment agreement, 1% after a levy notice).
Overlap: in months when both apply, the late-filing rate is 4.5% (5% − 0.5%).
Minimum: more than 60 days late → late-filing penalty is at least the lesser of the minimum ($525 in 2026, $510 in 2025, $485 in 2024) or the tax owed.
Interest = balance × ((1 + annual rate ÷ 365)days − 1), at the federal short-term rate + 3%.
Example: $5,000 owed, due April 15, 2026, filed August 20 (5 months or part) and paid October 24 (7 months or part). Late filing = $5,000 × 4.5% × 5 = $1,125. Late payment = $5,000 × 0.5% × 7 = $175. Interest at 7% compounded daily for 192 days adds about $188 on the tax and about $42 on the late-filing penalty.
How penalties grow on $10,000 of unpaid tax
Months late (filed and paid together)
Failure to file
Failure to pay
Total penalties
1
$450
$50
$500
3
$1,350
$150
$1,500
5
$2,250
$250
$2,500
12
$2,250
$600
$2,850
24
$2,250
$1,200
$3,450
50 or more
$2,250
$2,500
$4,750 (maximum)
Interest comes on top. On small balances the minimum penalty matters more: a return more than 60 days late with $400 owed gets a $400 late-filing penalty, the whole tax.
Tips to keep penalties down
File on time even if you can't pay: the late-filing penalty is ten times larger than the late-payment penalty.
Pay as much as you can by the due date; penalties and interest only apply to the unpaid part.
Ask for a short-term payment plan (up to 180 days) or an installment agreement to halve the monthly late-payment rate.
If you have a clean three-year record, request first-time abatement by phone or in writing.
Frequently asked questions
What is the IRS penalty for filing late?
The failure-to-file penalty is 5% of the unpaid tax for each month or part of a month the return is late, up to 25%. If the return is more than 60 days late, the penalty is at least the smaller of a fixed minimum ($525 for returns due in 2026) or 100% of the tax owed.
What is the IRS penalty for paying late?
The failure-to-pay penalty is 0.5% of the unpaid tax for each month or part of a month it stays unpaid, up to 25%. It drops to 0.25% a month while you are on an installment agreement for a return filed on time, and rises to 1% a month after the IRS issues a final notice of intent to levy.
What happens if both penalties apply?
For any month when both apply, the failure-to-file penalty is reduced by the failure-to-pay penalty for that month, so the combined charge is 5% a month. After five months the late-filing penalty is maxed out at 22.5% and the late-payment penalty keeps growing up to 25%.
Does a tax extension stop penalties?
An extension (Form 4868) gives you until October 15 to file, so it prevents the failure-to-file penalty if you file by then. It does not extend the time to pay: interest and the failure-to-pay penalty still run from April 15 on any tax not paid.
How does the IRS charge interest?
Interest is the federal short-term rate plus 3 percentage points, reset every quarter and compounded daily. It runs from the due date until the balance is paid, on the unpaid tax and also on penalties. Interest cannot be waived for reasonable cause.
Is there a penalty if I am owed a refund?
No. Both penalties are a percentage of unpaid tax, so if you are due a refund there is no penalty for filing late. You must file within three years of the due date to claim the refund.
Can IRS penalties be removed?
Often, yes. First-time abatement can remove failure-to-file and failure-to-pay penalties if you had no penalties in the prior three years and are now compliant, and reasonable cause relief covers events like serious illness or disasters. Interest on the abated penalty is removed too.
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