The late filing penalty for a federal income tax return is 5% of the tax you still owe for each month or partial month the return is overdue, capped at 25% of that unpaid balance. If the return is more than 60 days late, a minimum penalty of $525 or the full amount of unpaid tax (whichever is smaller) applies for returns due after December 31, 2025.1Internal Revenue Service. Failure to File Penalty The penalty is calculated on tax you owe, so a return that produces a refund carries no filing penalty at all.
How the 5% Monthly Charge Adds Up
The clock starts the day after the filing deadline and keeps ticking each month until you file. A partial month counts as a whole one, so filing on the first of a new month costs the same as filing on the last. Someone who owes $10,000 and files three months late owes $1,500 in filing penalties, on top of the tax itself.
The base is the tax still unpaid at the deadline, not your total liability. Paycheck withholding and estimated tax payments you already made reduce what the 5% is calculated against.2Office of the Law Revision Counsel. 26 US Code 6651 – Failure to File Tax Return or to Pay Tax Withhold $8,000 against a $10,000 bill and the penalty runs on the $2,000 gap.
The failure-to-pay penalty runs alongside the filing penalty at 0.5% per month, capped at its own 25%.3Internal Revenue Service. Failure to Pay Penalty When both apply in the same month, the IRS reduces the filing penalty by the payment penalty amount, so the combined charge stays at 5% per month rather than 5.5%. The effective filing rate during the overlap is 4.5%.1Internal Revenue Service. Failure to File Penalty
The practical lesson: not filing is ten times worse than not paying. If you can’t cover the bill, file anyway and face only the 0.5% monthly charge instead of the 5% one on top of it.
The $525 Minimum After 60 Days
Once your return is more than 60 days past the due date, a floor kicks in. For returns due after December 31, 2025, the minimum is $525 or 100% of the unpaid tax, whichever is less.1Internal Revenue Service. Failure to File Penalty Owe $200 and file 61 days late, and the penalty is the full $200. Owe $800, and it jumps to $525 rather than whatever the percentage math produces.
The IRS adjusts this floor for inflation. Returns due in 2025 carried a $510 minimum; returns due in 2024 were $485.1Internal Revenue Service. Failure to File Penalty
When the Penalty Is Zero
Because the calculation runs off unpaid tax, someone whose withholding and estimated payments covered the full liability owes no filing penalty regardless of how late the return arrives. The same is true for anyone due a refund.1Internal Revenue Service. Failure to File Penalty
There is still a good reason to file. You have three years from the original filing deadline to claim a refund. After that, the money belongs to the U.S. Treasury.4Office of the Law Revision Counsel. 26 US Code 6511 – Limitations on Credit or Refund If you never file, the window shrinks to two years from when the tax was actually paid, which for most people means paycheck withholding.
How an Extension Changes the Picture
Filing Form 4868 by the April deadline pushes your filing deadline to October 15. You can also skip the form by making an electronic payment before April and marking it as an extension request.5Internal Revenue Service. Get an Extension to File Your Tax Return File by October 15 and no 5% monthly penalty applies. Miss that extended date and the penalty starts running from October 15.1Internal Revenue Service. Failure to File Penalty
An extension buys time to file, not time to pay. Any tax still unpaid after April accrues the 0.5% monthly failure-to-pay penalty and daily interest, even with a valid extension in place.6Internal Revenue Service. Form 4868 – Application for Automatic Extension of Time To File US Individual Income Tax Return Estimate what you owe and send it in with the extension if you can.
Two groups get automatic extensions without filing the form. U.S. citizens and resident aliens whose main home and workplace are outside the United States and Puerto Rico on the April due date have until June 15, and so do military personnel stationed abroad.7Internal Revenue Service. US Citizens and Resident Aliens Abroad – Automatic 2-Month Extension of Time to File Service members in a designated combat zone get a much longer window: the total time in the zone plus 180 days after leaving, with no interest or penalties during that period.8Internal Revenue Service. Extension of Deadlines – Combat Zone Service
Interest Runs Alongside the Penalty
Interest is a separate cost. It accrues on unpaid tax from the original due date, compounds daily, and has no cap.9Internal Revenue Service. Interest For the first quarter of 2026, the individual underpayment rate is 7% per year.10Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 The rate resets quarterly at the federal short-term rate plus three percentage points.11Internal Revenue Service. Quarterly Interest Rates
Interest also runs on the penalty itself once it is assessed, starting from the return’s original (or extended) due date.9Internal Revenue Service. Interest That is why an old, ignored tax bill can grow well past the original amount.
Getting the Penalty Removed
Two forms of relief cover most situations, and the first one is easier to qualify for than most people expect.
First-Time Abatement
If you filed all required returns for the three tax years before the penalty year and had no penalties during that period (or had any earlier ones removed for an acceptable reason), you can request first-time abatement.12Internal Revenue Service. Administrative Penalty Relief It covers the failure-to-file, failure-to-pay, and failure-to-deposit penalties. It does not touch interest.
Call the number on the IRS notice you received. Many requests are approved on the same call.13Internal Revenue Service. Penalty Relief If the representative can’t approve it by phone, you can submit Form 843 in writing.14Internal Revenue Service. About Form 843, Claim for Refund and Request for Abatement
Reasonable Cause
If your compliance history doesn’t qualify you for first-time abatement, you can still show reasonable cause. You need to demonstrate that you used ordinary care but couldn’t file on time because of circumstances beyond your control.15Internal Revenue Service. Penalty Relief for Reasonable Cause Serious illness, a death in the immediate family, destruction of records by fire or natural disaster, and reliance on incorrect advice from a tax professional are common grounds. Have documentation ready: hospital records, insurance claims, letters from the professional you relied on.
Disaster-Area Postponements
When FEMA declares a disaster with Individual Assistance, the IRS automatically postpones filing and payment deadlines for affected residents, area business owners, and relief workers.16Internal Revenue Service. Disaster Assistance and Emergency Relief for Individuals and Businesses The new dates vary by event, so check the IRS disaster relief page for the current list.
A Note on Partnerships and S Corporations
The 5% rule is for individual income tax returns. Partnership returns (Form 1065) and S corporation returns (Form 1120-S) use a flat structure: $255 per partner or shareholder per month, for up to 12 months, whether the entity owes tax or not.1Internal Revenue Service. Failure to File Penalty A four-partner LLC filing six months late owes $6,120. First-time abatement and reasonable cause relief are both available for these penalties as well.12Internal Revenue Service. Administrative Penalty Relief