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What are reasonable cause and good faith defenses for IRS penalties?

Filing Mistakesadvanced2 answers · 5 min readUpdated February 28, 2026

Quick Answer

Reasonable cause and good faith defenses can eliminate IRS penalties if you can prove circumstances beyond your control prevented timely compliance. The IRS approves reasonable cause relief in about 40% of cases, with common examples including death in family, serious illness, natural disasters, or reliance on incorrect professional advice.

Best Answer

DF

Diana Flores, Tax Credits & Amendments Specialist

People who received IRS penalty notices and want to understand their options for relief

Top Answer

What qualifies as reasonable cause for penalty relief?


Reasonable cause exists when you exercised ordinary business care and prudence but were unable to comply with tax obligations due to circumstances beyond your control. According to IRS Publication 5307, the IRS considers several factors when evaluating reasonable cause claims.


Common reasonable cause situations include:

  • Death, serious illness, or unavoidable absence of taxpayer or immediate family
  • Fire, casualty, natural disaster, or other disturbances
  • Unable to obtain records necessary to file returns
  • Errors or delays by the IRS in processing
  • Incorrect advice from IRS employees
  • Incorrect advice from tax professionals (in specific circumstances)

  • Example: Medical emergency penalty relief


    Sarah was hospitalized for three weeks in March 2026, during her busiest tax season as a freelance graphic designer. She couldn't file her return by April 15 and received a $435 failure-to-file penalty on her $8,700 tax liability. She submitted Form 843 with:

  • Hospital records showing her admission dates
  • Doctor's letter confirming she was incapacitated
  • Evidence she filed as soon as possible after recovery

  • The IRS granted full penalty relief because her hospitalization was beyond her control and she acted reasonably upon recovery.


    Good faith defense vs. reasonable cause


    Reasonable cause focuses on external circumstances that prevented compliance. Good faith demonstrates you made an honest attempt to comply with tax law, even if you made an error.


    Good faith is particularly relevant for:

  • Accuracy-related penalties (20% of underpayment)
  • Reliance on tax professional advice
  • Complex tax situations with unclear guidance

  • Documentation requirements for penalty relief


    The IRS requires specific documentation to support your claim:



    How to request penalty relief


    Step 1: Determine which penalties you're challenging. Common penalties include:

  • Failure to file: 5% per month (max 25%) of unpaid taxes
  • Failure to pay: 0.5% per month (max 25%) of unpaid taxes
  • Accuracy-related: 20% of the underpayment
  • Estimated tax: Variable based on underpayment amount

  • Step 2: Complete Form 843 (Claim for Refund and Request for Abatement) or write a penalty abatement letter. Include:

  • Specific penalties you're requesting relief from
  • Detailed explanation of circumstances
  • Supporting documentation
  • Timeline showing you acted reasonably

  • Step 3: Submit your request to the IRS address on your penalty notice. Allow 8-12 weeks for processing.


    First-time penalty abatement (FTA)


    Before pursuing reasonable cause, check if you qualify for first-time penalty abatement. This administrative relief is available if you:

  • Have no penalties for the three tax years prior to the penalty year
  • Filed all required returns or extensions
  • Paid or arranged to pay any taxes owed

  • FTA can eliminate failure-to-file and failure-to-pay penalties without proving reasonable cause. It's often easier to obtain than reasonable cause relief.


    What you should do


    1. Review your penalty notice to identify specific penalties and amounts

    2. Check if you qualify for first-time penalty abatement (easier option)

    3. If not, gather documentation supporting reasonable cause or good faith

    4. Use our form-explainer tool to understand your penalty notice details

    5. Submit Form 843 or penalty abatement letter with supporting evidence

    6. Consider professional help for penalties over $1,000 or complex situations


    Key takeaway: The IRS approves reasonable cause relief in about 40% of cases when proper documentation is provided. Focus on proving circumstances were beyond your control and that you acted reasonably once able to comply.

    *Sources: [IRS Publication 5307](https://www.irs.gov/pub/irs-pdf/p5307.pdf), [Treasury Regulation 1.6664-4](https://www.ecfr.gov/current/title-26/chapter-I/subchapter-A/part-1/section-1.6664-4)*

    Key Takeaway: Reasonable cause relief is available when circumstances beyond your control prevented tax compliance, with the IRS approving about 40% of properly documented requests.

    Common penalty types and relief options available

    Penalty TypeRateMaximumFTA EligibleCommon Reasonable Cause
    Failure to File5% per month25% of tax owedYesMedical emergency, disaster
    Failure to Pay0.5% per month25% of tax owedYesFinancial hardship, IRS error
    Accuracy-Related20% of underpayment20% of underpaymentNoProfessional advice, good faith
    Estimated TaxVariableNo maximumNoSafe harbor met, hardship

    More Perspectives

    MW

    Michelle Woodard, Tax Policy Analyst

    Taxpayers who already have penalty notices and need to respond quickly

    Time limits for penalty relief requests


    When you receive an IRS penalty notice, time is critical. You typically have three years from the date you filed the return or two years from the date you paid the penalty to request a refund. However, for penalty abatement, it's best to respond within 60 days of receiving the notice.


    Strategic approach to multiple penalties


    Many taxpayers face multiple penalties simultaneously. For example, if you filed late and paid late, you might have both failure-to-file (5% per month) and failure-to-pay (0.5% per month) penalties. The failure-to-file penalty is reduced by the failure-to-pay penalty for overlapping months, so your combined penalty is capped at 5% per month.


    Example penalty calculation:

  • Tax owed: $5,000
  • Filed 3 months late, paid 3 months late
  • Failure-to-file: $750 (15% of $5,000)
  • Failure-to-pay: $75 (1.5% of $5,000)
  • Net penalty offset: $675 total (failure-to-file reduced by failure-to-pay)

  • Professional advice defense specifics


    Relying on tax professional advice can support both reasonable cause and good faith defenses, but specific conditions must be met:

  • The advisor must be qualified (CPA, EA, attorney, or enrolled retirement plan agent)
  • You must provide all relevant facts to the advisor
  • The advice must be received before the action was taken
  • You must reasonably rely on the advice

  • This defense is particularly strong for complex areas like depreciation, business expense classifications, or retirement plan distributions where professional judgment is expected.


    What to do immediately upon receiving a penalty notice


    1. Don't ignore it - Penalties compound with interest

    2. Verify the penalty calculation using IRS penalty computation worksheets

    3. Check for first-time abatement eligibility before preparing reasonable cause arguments

    4. Gather contemporaneous documentation - records created at the time of the issue are stronger than after-the-fact explanations

    5. Consider partial payment to stop interest accrual while disputing penalties


    Key takeaway: Respond to penalty notices within 60 days for best results, and always check first-time penalty abatement eligibility before investing time in reasonable cause documentation.

    Key Takeaway: Act quickly when receiving penalty notices - respond within 60 days and check first-time abatement eligibility before preparing complex reasonable cause arguments.

    Sources

    irs penaltiespenalty reliefreasonable causegood faithtax compliance

    Reviewed by Michelle Woodard, Tax Policy Analyst on February 28, 2026

    This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.