IRS Penalty & Interest Calculator (CP14)

How this calculator works

Frequently asked questions

Is this the same as the Form 2210 estimated-tax penalty?

No — different penalty entirely. This calculator models FAILURE-TO-FILE and FAILURE-TO-PAY penalties on a return you filed or paid late (the CP14 scenario). The Form 2210 estimated-tax underpayment penalty applies when you underpaid your quarterly estimates during the year — even if you file and pay on time. Use /calculators/estimated-tax-penalty for that one.

Does filing an extension stop the penalties?

Mostly it stops the failure-to-file penalty — and only if you actually file by October 15. Interest keeps running from the original April 15 due date regardless of the extension, and so does the failure-to-PAY penalty unless you paid at least 90% of your total tax by April 15 (withholding, estimated payments or the Form 4868 payment) and pay the rest with a return filed by October 15. Then the IRS treats you as having reasonable cause and charges no failure-to-pay penalty for the extension period. Form 4868 is an extension to FILE, not to PAY.

How does the concurrent-month offset work?

In any month when both penalties apply, IRC §6651(c)(1) reduces the 5% failure-to-file by the 0.5% failure-to-pay, so the combined rate is 5% (not 5.5%). This calculator applies that offset — most competitor tools double-count.

Can I get these penalties removed?

Often, yes. For a 2025 or later return, the IRS's Automatic Exemption from Penalty (AEP) keeps failure-to-file and failure-to-pay from being assessed at all when your three prior years are clean; answer the three-year question above to see your figures without them. For earlier returns, First-Time Penalty Abatement does the same on request if you have three prior clean years. See the CP14 guide for the phone-call script and Form 843 instructions. Interest on removed penalties is removed too, but interest on the underlying tax is statutory and generally not abatable.

Does an installment agreement reduce the penalty?

Yes, if you filed the return on time (extensions count). For each month a valid IRS installment agreement is in effect, the failure-to-pay rate drops from 0.5% to 0.25%; months before the agreement started stay at 0.5%. Toggle the installment-agreement switch and enter the date it took effect to model it.

How accurate is the interest number?

It's an estimate. We apply the published quarterly rate (federal short-term + 3%) to your unpaid tax from the due date, and to the failure-to-file penalty from the return's due date including any extension (IRC §6601(e)(2)(B)), using the same rate schedule as our Form 2210 calculator. Interest on the failure-to-pay penalty isn't included: it starts only after the IRS bills that penalty (IRC §6601(e)(2)(A)). Like the IRS, we compound it daily (IRC §6622(a)). Your notice can still differ by a few dollars, for example from payments or credits the IRS applied that aren't entered here.

Will the IRS remove these penalties automatically?

Starting with tax year 2025 returns, yes — the IRS's new Automatic Exemption from Penalty (AEP) program suppresses failure-to-file, failure-to-pay, and failure-to-deposit penalties at return processing for taxpayers with three prior clean years, no request needed, and it becomes the sole remedy for returns originally due on or after January 1, 2027. During the summer-2026 phase-in, a qualifying TY2025 return may still draw a CP14; if so, request First-Time Penalty Abatement the traditional way (phone call or Form 843). See the IRS Automatic Penalty Relief (AEP) guide at /guides/irs-automatic-penalty-relief for the full breakdown.