What Late Fees Apply When You File Taxes After the Deadline

The IRS charges a failure-to-file penalty if you submit your return after the important date, separate from any penalty for owing tax you did not pay on time

The failure-to-file penalty is 5% of the unpaid tax for each month or part of a month your return is late, up to a maximum of 25%. This penalty applies only if you owe tax when you file — if you are due a refund, the IRS does not charge this penalty, though you will still lose money by filing late because your refund takes longer to arrive.

If you file more than 60 days after the important date (or the extended important date if you requested one), the minimum penalty is the smaller of $435 or 100% of the unpaid tax, whichever is less. This floor exists so that even a small unpaid balance triggers a meaningful penalty if you are very late.

The failure-to-file penalty and the failure-to-pay penalty (which is 0.5% per month for unpaid tax) can run at the same time, though the combined rate caps at 1% per month. The IRS will reduce or remove these penalties if you show reasonable cause — for example, a death in the family, a serious illness, or reliance on a tax professional who made an error — but you must request this in writing and provide documentation.

Key Takeaways

The failure-to-file penalty is 5% of unpaid tax per month, up to 25% total, and applies only if you owe money when you file.
If you file more than 60 days late, the minimum penalty is $435 or your unpaid tax, whichever is smaller.
The failure-to-file and failure-to-pay penalties can overlap, but the combined rate does not exceed 1% per month.
You can request penalty relief by submitting Form 843 (Claim for Refund and Request for Abatement) with documentation of reasonable cause.
Filing late does not change your tax liability itself, only adds penalties and interest on top of what you owe.

How the 5% monthly penalty is calculated

The penalty is based on the tax you owe, not the total income you reported. If your return shows $10,000 in unpaid tax and you file two months late, the penalty is 5% × 2 months × $10,000 = $1,000. If you file four months late, it becomes 5% × 4 months × $10,000 = $2,000, but it stops at the 25% cap, so the maximum would be $2,500.

The IRS counts any part of a month as a full month. If you file one day into the second month after the important date, you owe the penalty for two months. This is why filing even a few days late can cost more than waiting until the next month.

The penalty clock starts on the original important date (usually April 15) or your extended important date (usually October 15 if you filed Form 4868), whichever is later. If you requested an extension and filed by October 15, no penalty applies. If you requested an extension but filed on October 20, the penalty runs from April 15, not October 15.

When you owe nothing and file late

If your return shows a refund due to you, the IRS does not charge a failure-to-file penalty. However, you still lose money because the IRS will not process your refund until it receives your return. A refund that would have arrived in May if you filed on time might not arrive until August or later if you file in July.

Interest on a refund owed to you accrues at the federal rate set each quarter, currently around 8% annually, but the IRS does not pay you that interest unless your refund is delayed beyond a certain point — usually 45 days after you file. Filing late does not trigger interest in your favor; it straightforward delays when you receive money that is already yours.

Interest charges on unpaid tax

Separate from penalties, the IRS charges interest on any tax you owe but do not pay by the original important date. The interest rate is set quarterly and is currently around 8% annually, compounded daily. Interest accrues whether you file on time or late, so it is not a penalty for late filing — it is the cost of borrowing from the government.

If you owe $5,000 and file six months late, you will owe the $5,000 plus interest for those six months plus the failure-to-file penalty. The three charges stack: the original tax, interest, and the penalty. This is why the total amount due can grow significantly if you delay.

How to request penalty relief

You can ask the IRS to reduce or remove a penalty by filing Form 843 (Claim for Refund and Request for Abatement). You must submit it within three years of the date you filed your return or two years from the date you paid the tax, whichever is later. The form asks you to describe the reason you filed late and to provide supporting documents.

The IRS recognizes several categories of reasonable cause: death, serious illness, or unavoidable absence; reliance on a tax professional's error; first-time penalty (if you have a clean record, the IRS may remove a penalty on your first offense); or circumstances beyond your control, such as a natural disaster or fire that destroyed your records.

You do not need to file Form 843 when ready. If you receive a notice from the IRS that includes a penalty, you can respond to that notice directly and request abatement there. The IRS will review your explanation and either grant relief, deny it, or offer a partial reduction. There is no cost to request relief, and you can appeal if the IRS denies your request.

The difference between filing late and paying late

Filing late and paying late trigger different penalties. The failure-to-file penalty (5% per month) applies when you do not submit your return by the important date. The failure-to-pay penalty (0.5% per month) applies when you do not pay the tax shown on your return by the important date, even if you filed on time.

If you file on time but do not pay, you owe the failure-to-pay penalty plus interest, but not the failure-to-file penalty. If you file late and also do not pay, both penalties explore, but they do not exceed 1% per month combined. For example, if you file two months late and owe $10,000, the combined penalty is 1% × 2 months × $10,000 = $200, not the full 5% + 0.5% = 5.5%.

Extensions and how they affect the important date

Filing an extension with Form 4868 (process for Automatic Extension of Time To File U.S. Individual Income Tax Return) moves your important date from April 15 to October 15. The extension is automatic — you do not need approval — but you must file the form by the original April 15 important date. Filing the form does not extend the important date to pay tax; it only extends the important date to file your return.

If you file by October 15 with an extension, no failure-to-file penalty applies. If you file after October 15, the penalty runs from April 15, not October 15. An extension also does not reduce interest or penalties on unpaid tax — those accrue from April 15 regardless of whether you extended the filing important date.

Frequently Asked Questions

Can I get the penalty removed if I filed late by accident?

Yes, you can request removal by filing Form 843 and explaining the circumstances. The IRS considers reasonable cause, which includes reliance on a tax professional's error, a serious illness, or circumstances beyond your control. First-time penalties are often reduced or removed if you have a clean record. You will need to provide supporting documents, such as a letter from your accountant or medical records.

What if I file late but the IRS owes me a refund?

You will not owe a failure-to-file penalty, but you will lose the refund you would have received if you filed on time. The IRS will not pay interest on your refund unless it is delayed beyond 45 days after you file. Filing late straightforward means your refund arrives later than it would have otherwise.

Does an extension protect me from penalties if I file after October 15?

An extension protects you only if you file by October 15. If you file after October 15, the failure-to-file penalty runs from April 15, not October 15. The extension gives you six extra months to file, but does not give you a grace period after October 15.

How much interest will I owe on unpaid tax?

Interest is set quarterly by the IRS and is currently around 8% annually, compounded daily. The exact rate depends on the quarter in which you owe the tax. Interest accrues from the original April 15 important date until you pay, whether you file on time or late. You can find the current rate on the IRS website.

Can I pay the penalty in installments?

Yes, if you cannot pay the full amount at once, you can set up a payment plan with the IRS. You can request an installment agreement by calling the IRS or submitting Form 9465 (Installment Agreement Request). The IRS charges a setup fee and interest continues to accrue on the unpaid balance, but a payment plan allows you to spread the cost over time.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.