IRS Penalties: Failure to File, Pay and Estimate

By Tom, CPA · Updated October 27, 2026

Part of: Tax Planning

TL;DR: Filing late costs 5% a month; paying late costs 0.5%. File even if you cannot pay. Safe harbors avoid the estimated tax penalty, and First Time Abate can remove first-offense filing and payment penalties.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

The IRS penalty system is a buffet nobody ordered from. There is a penalty for filing late, a different one for paying late, another for not paying enough during the year, one for being inaccurate, and interest layered over all of them like gravy. The tax code is 4 million words long; you need about 400 of them to know which penalties are big, which are small, which stack, and which the IRS will take back if you ask nicely and have a clean history.

This guide covers the failure-to-file penalty, the failure-to-pay penalty, the estimated tax penalty, the accuracy-related penalty, how interest works, and the main relief options, including First Time Abate and reasonable cause. Rates and amounts are as of Oct 2026, per IRS guidance.

CPA Warning Label: Penalty abatement does not remove interest on the tax itself. Ask for First Time Abate before reasonable cause if you qualify.

The penalty menu at a glance

Interest applies on top of unpaid tax and, generally, on unpaid penalties too.

Failure to file: the big one

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, a minimum penalty applies: for returns required to be filed in 2026, the lesser of $525 or 100% of the tax owed, per the IRS failure-to-file penalty page.

When failure-to-file and failure-to-pay apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount for that month, so the combined rate is 5% per month for the first five months.

The lesson is simple and slightly absurd: the penalty for not sending paper is ten times the penalty for not sending money. If you cannot pay, file anyway. If you need time, file an extension; see our extension guide.

If you are owed a refund, there is no failure-to-file penalty, because it is computed on unpaid tax. But refunds not claimed within three years are forfeited.

Failure to pay: small but persistent

The failure-to-pay penalty is 0.5% of unpaid tax per month or part of a month, up to 25%. Two adjustments, per the IRS:

• It rises to 1% per month starting 10 days after the IRS issues a notice of intent to levy.
• It drops to 0.25% per month while an approved installment agreement is in effect, if you filed on time.

At 0.5% a month, the penalty takes 50 months to max out, which tells you the IRS is patient but never forgetful.

Estimated tax penalty

The U.S. tax system is pay-as-you-go. If withholding and quarterly estimates fall short during the year, you can owe an underpayment penalty, figured on Form 2210 and based on the IRS underpayment interest rate and how long each installment was short.

You generally avoid it if you owe less than $1,000 after withholding and credits, or if you paid at least the smaller of:

• 90% of the current year's tax, or
• 100% of the prior year's tax (110% if prior-year AGI was over $150,000, or $75,000 if married filing separately).

Withholding is treated as paid evenly through the year regardless of when it actually happened, which makes a late-year withholding increase a handy patch. Uneven income? The annualized income installment method on Form 2210 can reduce the penalty. Waivers exist for casualty, disaster or other unusual circumstances, and for retirees (age 62+) or people who became disabled, if the underpayment was due to reasonable cause.

See why you owe or get a refund for how withholding fits in.

Accuracy-related penalty

A 20% penalty applies to the portion of an underpayment due to negligence or disregard of rules, or to a substantial understatement of income tax. For individuals, an understatement is substantial if it exceeds the greater of 10% of the correct tax or $5,000.

Defenses include reasonable cause and good faith, adequate disclosure of a position with a reasonable basis, and reasonable reliance on a competent, informed professional. Documentation is what turns "I meant well" into a defense. This penalty most often appears after an audit or CP2000; see our audit guide.

Interest: the part you cannot abate (mostly)

The IRS charges interest on unpaid tax from the original due date until paid. For individuals, the rate is the federal short-term rate plus 3 percentage points, set quarterly and compounded daily, per IRS Topic 653. Interest also generally runs on penalties.

Interest is generally not removed for reasonable cause. It is reduced automatically when the underlying penalty is abated, and in limited cases it can be abated for unreasonable IRS errors or delays.

Personal interest paid to the IRS is not deductible for individuals. Interest on the deductible kind of debt is another story: see our mortgage interest guide, rental mortgage interest and the new car loan interest deduction.

Getting penalties removed

First Time Abate

The IRS offers administrative relief for failure-to-file, failure-to-pay and failure-to-deposit penalties if you:

• had no penalties (other than an estimated tax penalty) in the prior three tax years,
• filed all currently required returns or valid extensions, and
• paid, or arranged to pay, the tax due.

You can often request it by phone, by responding to the notice, or with Form 843. It does not apply to the estimated tax or accuracy-related penalties.

Reasonable cause

If you exercised ordinary business care and still could not comply, for example due to serious illness, a death in the family, a natural disaster or inability to get records, you can request relief with an explanation and supporting documents. "I forgot" and "my software was confusing" are not reasonable cause, though they are very relatable.

Statutory exceptions and disasters

Written erroneous advice from the IRS and disaster postponements can also eliminate penalties.

Prevention checklist

• File on time or extend, every year, even with no money to pay. It neutralizes the largest penalty.
• Hit a safe harbor for estimates: track prior-year tax and pay 100% or 110% of it through withholding and quarterly payments if income is volatile.
• Fix withholding mid-year after a raise, bonus, side income or a big capital gain. Withholding counts as paid evenly through the year.
• Reconcile every 1099 before filing, to avoid CP2000 mismatches and accuracy penalties.
• Document judgment calls: business use percentages, mileage logs, reasonable salary studies, valuations.
• Open every IRS letter. Response deadlines matter, and the 1% levy-rate penalty starts after a notice you might be ignoring.
• Use a payment plan if you cannot pay in full; the failure-to-pay rate drops to 0.25%.
• Save your First Time Abate for a real emergency; it resets only after three clean years.

Our tax planning calendar puts the estimate and filing dates in one place.

Illustration: the cost of not filing

Avery owes $10,000 of 2025 tax, due April 15, 2026, and files and pays on September 1, 2026, about 4.5 months late, counted as 5 months.

• Failure to pay: 0.5% x 5 = 2.5%, or $250.
• Failure to file: 5% x 5 = 25%, reduced by the 2.5% failure-to-pay amount, so 22.5%, or $2,250.
• Combined penalties: $2,500, plus interest.

Had Avery filed on time (or extended) and paid on September 1, the penalty would have been about $250 plus interest. Same money, same date, a $2,250 difference for the paperwork alone. If Avery had a clean three-year record, First Time Abate could remove the penalties, though not the interest on the tax. Illustrative only.