Calculator
US Late-Filing Penalty Estimator
Filed your US return late, or not yet at all? The IRS charges a failure-to-file penalty of 5% of unpaid tax per month (capped at 25%) and a failure-to-pay penalty of 0.5% per month (also capped at 25%). This tool gives an indicative maximum — and shows why the penalty is often zero when reliefs cancel your US tax, and how catch-up routes can remove them entirely.
Estimate your US late-filing penalties
Enter the US tax you still owe and how many months late the return is. This gives an indicative maximum of the two main IRS civil penalties — it does not include interest, and assumes US tax is actually due after reliefs.
The unpaid balance — not your income. If the Foreign Tax Credit or FEIE eliminates your US tax, enter 0.
Counted from the deadline that applies to you. Americans abroad get an automatic extension to 15 June.
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Frequently asked questions
The main civil penalty is the failure-to-file penalty: 5% of unpaid tax per month or part-month late, capped at 25%. A separate failure-to-pay penalty of 0.5% per month, also capped at 25%, applies to tax paid late. In months where both apply, the combined charge is 5% per month for the first five months, then 0.5% per month. Interest accrues separately.
Yes. US citizens and residents living outside the United States receive an automatic extension to 15 June, and can request a further extension to 15 October. Any tax owed still accrues interest from the original April deadline.
Often, yes. Penalty relief may be available through First-Time Abate or reasonable-cause arguments. For expats who fell behind non-wilfully, the Streamlined Filing Compliance Procedures can remove penalties entirely. The delinquent-FBAR route may also carry no penalty where tax returns were otherwise correct.
The failure-to-file and failure-to-pay penalties are a percentage of unpaid tax. If the Foreign Tax Credit or FEIE reduces your US tax to zero, these percentage penalties are generally zero too. The return must still be filed, and separate flat-rate penalties apply to missed information returns.
It gives an indicative maximum using headline statutory rates. It excludes interest, the reduced failure-to-pay rate once an instalment agreement is in place, and any penalty abatement. It is educational, not a penalty determination.
Facing a penalty notice — or worried about one?
Late-filing penalties can often be reduced or removed entirely through the right catch-up route or a reasonable-cause claim. Book a consultation and we will map the safest, lowest-cost way back into compliance.