IRS Late Filing Penalty Calculator 2026: Failure to File, Failure to Pay & Interest

How to use the IRS penalty calculator

Pick the return, enter the tax that was still unpaid on April 15 (the balance after withholding, estimated payments and anything you paid with an extension), say whether you filed Form 4868 on time, and enter the date you filed and the date you paid, or will. The result splits the bill into the failure-to-file penalty, the failure-to-pay penalty and interest, shows the month-by-month overlap, and shows what is left if first-time abatement removes the penalties.

• If you are owed a refund, enter 0: there is no failure-to-file penalty when no tax is due.
• Future dates are fine: use them to see what waiting another month costs.
• Choose the payment plan option only if you filed on time; the lower 0.25% rate applies only then.

IRS late filing penalties 2026: the rules

Both penalties come from section 6651 of the Internal Revenue Code and are charged per month or part of a month, so filing one day into a new month costs a full month.

Minimum penalty for a return more than 60 days late

The minimum is indexed for inflation each year and depends on when the return was due. It only bites on small balances: anyone who owes more than about $3,900 reaches it anyway after three months. Example: $400 owed on a 2025 return filed and paid on July 20, 2026. The regular calculation gives $72.00, but because the return was more than 60 days late the filing penalty is raised to $400, all of the tax.

How the IRS counts the months

The first month starts the day after the due date and ends on the same date of the next month. For a return due April 15, month one runs April 16 to May 15, month two from May 16 to June 15, and so on. A valid extension moves the start of the filing penalty to October 15, even if you then file after October 15, but the amount is still the tax unpaid on April 15. The payment penalty always counts from April 15, because an extension never extends the time to pay.

The table shows a $5,000 balance on a 2025 return under different dates, using the calculator.

IRS interest rates for 2024, 2025 and 2026

Interest is the federal short-term rate plus 3 percentage points, reset each quarter and compounded daily. It runs on unpaid tax from the original due date, extension or not. On the failure-to-file penalty it runs from the due date of the return including extensions. On the failure-to-pay penalty it starts only after the IRS sends a bill and you do not pay within 21 days, so the calculator leaves it out. The rate for the first quarter of 2027 is normally announced in mid-November; until then the calculator assumes the current 7%.

How to get IRS penalties removed

The penalty for not paying enough estimated tax during the year (Form 2210) is separate. It works like interest at the same quarterly rates and is not removed by first-time abatement.

• First-time abatement: if you filed the same type of return on time for the prior three years and had no penalties in that period (other than an estimated tax penalty), the IRS removes failure-to-file and failure-to-pay penalties regardless of amount. Ask by phone or on Form 843. Interest on the tax is not removed, but interest on the removed penalties is.
• Reasonable cause: fire, disaster, serious illness, death in the family, or being unable to get records despite trying. Decided case by case.
• The 90% extension rule: with a valid extension, if at least 90% of the tax was paid by April 15 and the rest is paid with the return by the extended date, no failure-to-pay penalty applies for the extension period.
• Disaster postponements: if your county is covered, penalties do not start until the postponed date.