| Failure to File Return | 5% of unpaid tax per month | Max 25%; Minimum $510 if >60 days late |
| Failure to Pay Tax | 0.5% per month (1% if after levy) | Max 25%; 0.25% if in installment agreement |
| Combined Failure to File & Pay | Up to 5% per month (4.5% file + 0.5% pay) | Max ~47.5% |
| Interest on Unpaid Tax | ~7% annually (compounded daily) | Based on federal short-term rate + 3% |
| Underpayment of Estimated Tax | Interest-based penalty | Avoid if 90% of current year tax or 100–110% of last year’s paid |
| Information Returns (W-2/1099) | $60–$340 per form | Intentional disregard: $680+ per form, no cap |
| Accuracy-Related Penalty | 20% of tax underpayment | 40% for gross misstatements |
| Civil Fraud Penalty | 75% of tax underpayment | Requires IRS proof of fraud |
| Frivolous Return Penalty | $5,000 | For knowingly false or invalid filings |
| Payroll Tax Deposit Late | 2–15% of unpaid taxes | Increases with lateness stages |
| Trust Fund Recovery Penalty (TFRP) | 100% of unpaid trust fund taxes | Personally liable |
| Fail to Furnish W-2/1099 to Payee | $310 per form | Separate from filing penalty |
| Fail to File 1065 / 1120S | $245 per owner per month (up to 12 months) | Up to $11,760+ for 4-person firm |
| Excess IRA/HSA Contributions | 6% of excess amount | Annual until corrected |
| Early Retirement Withdrawal | 10% of withdrawal | Before age 59½; exceptions apply |
| Fail to File FBAR (Foreign Bank Account) | $10,000 (non-willful); up to $100K+ or 50% of account (willful) | Criminal charges possible |
| Fail to File Form 8938 (FATCA) | $10,000 initial; $50,000 for continued failure | Additional tax penalties may apply |
| ACA Shared Responsibility (Employers) | $241.67–$362.50 per employee per month | IRC §4980H(a/b); ~ $2,900–$4,350/year |
| Excess Advance Premium Tax Credit | Repayment required | Based on income discrepancy |
| BOI Reporting Penalty (FinCEN 2025) | $591 per day; up to $10,000 + jail (2 years) | New in 2024/25; applies to business owners |
| Nonprofit Late Form 990 Filing | $20–$110 per day | Up to $56,000; 3-year lapse = auto revocation |
| Expatriation Tax | Tax on deemed sale of worldwide assets | Applies to covered expatriates |
| Tax Evasion (Criminal) | Up to $250,000 fine + 5 years prison | Requires willful intent |
| Willful Failure to File or Pay | Up to $100,000 fine + 1 year prison | Criminal offense |
| Aiding/Assisting Fraud | Up to 3–5 years in prison + fines | For preparers or others involved in fraud |
