Overview

The statute of limitations defines how long the IRS can examine a return, assess additional tax, or propose adjustments. For most individual and business income tax returns the default period is three years from the later of the return’s due date or the date the return was filed (see IRS Pub. 556) (https://www.irs.gov/pub/irs-pdf/p556.pdf).

Key time limits

  • Three-year rule: The IRS generally has three years to assess tax from the later of the return’s due date or the date filed. This is the most common timeframe for audits and assessments (IRS Pub. 556) (https://www.irs.gov/pub/irs-pdf/p556.pdf).
  • Six-year rule: If a taxpayer omits more than 25% of gross income on a return, the assessment period generally extends to six years (IRC §6501(e); see IRS guidance) (https://www.irs.gov/individuals/international-taxpayers/statute-of-limitations).
  • No time limit: There is no statute of limitations if a return was not filed or if the IRS can prove the return was fraudulent. In those situations the IRS may assess at any time.

Extensions and agreements

  • Consent to extend: Taxpayers can sign Form 872 (Consent to Extend the Time to Assess Tax) to give the IRS more time to examine the return; many audit negotiations use this to preserve the assessment window (see IRS Form 872) (https://www.irs.gov/forms-pubs/about-form-872).
  • Filing late vs. filing on time: If you file after the original due date, the clock runs from the date you filed. If you filed on extension, the three‑year period generally starts from the extended due date.

Special situations

  • Amended returns: Filing an amended return does not automatically restart the statute for the original return; however, an amended return can create new exposure depending on what changes are made.
  • Foreign income: Significant unreported foreign income may trigger the six-year rule or other enforcement actions—special rules can apply (IRS guidance) (https://www.irs.gov/individuals/international-taxpayers/statute-of-limitations).
  • Collections vs. assessments: Separately, once the IRS assesses tax, it generally has 10 years to collect (IRC §6502)—a different statute than the assessment/audit window.

Practical tips (from practice)

  • Keep records at least six years: Because of the six‑year rule for significant omissions, keep tax records for at least six years (longer if you think fraud or an unfiled year could be an issue). For organization and audit defense, see our guide on record retention (Record Retention Policies That Protect You During Audits) (https://finhelp.io/glossary/record-retention-policies-that-protect-you-during-audits/).
  • Verify filing dates: When concerned about exposure, confirm the filing date on your IRS account transcript or your proof of filing; the statute runs from the later of due date or filed date.
  • Don’t assume safety after three years: If the IRS alleges a substantial omission, fraud, or you didn’t file, the three‑year clock may not protect you.
  • If audited, know your rights: Understand what the IRS must provide and what you can request—see our article on taxpayer rights during audits (Taxpayer Rights During an Audit: What the IRS Must Provide) (https://finhelp.io/glossary/taxpayer-rights-during-an-audit-what-the-irs-must-provide/).

Common misconceptions

  • Myth: ‘‘If three years pass I can’t be touched.’’ Reality: Only if the return was properly filed and there is no substantial omission or fraud. Agreements (Form 872) or special facts can extend or eliminate the limitation.

Short examples

  • Normal filing: A return due April 15, 2023 and filed April 10, 2023—IRS assessment window generally ends April 15, 2026.
  • Late filing: Same return filed October 1, 2023—assessment window generally ends October 1, 2026 (three years from the filing date).
  • Big omission: If the taxpayer omitted more than 25% of gross income on the 2022 return, the window can extend to six years.

Frequently asked questions

Q: How can I confirm whether the IRS can still assess a year?
A: Compare the later of the due date or filed date to today’s date and check for any signed extension Form 872. You can also request your IRS account transcript or work with a tax professional to confirm.

Q: What if the IRS sends a notice after the statute has expired?
A: Do not ignore it. Respond promptly and point to the statute if applicable—keep copies of filing proofs and consider professional representation.

Sources and authority

Disclaimer

This article is educational and general in nature and does not replace advice from a qualified tax professional. For guidance tailored to your situation, consult a CPA or tax attorney.