Quick answer: The IRS generally has three years after a return is filed—or its due date when filed early—to assess additional tax. The period can be six years for a substantial omission of gross income, and no assessment deadline applies to a fraudulent return or when no return is filed. Other special statutes also exist.
This guide translates the controlling rule into filing and recordkeeping steps. It reflects official material available on August 17, 2026. Tax-year forms, software features, state rules and agency procedures can change, so use the instructions for the exact year and transaction involved.
At a glance
| Question | Practical answer |
|---|---|
| Who this applies to | Individuals and businesses planning record retention or responding to an examination |
| What this does not cover | The separate ten-year collection period after assessment or every special international reporting statute |
| Where it is handled | The examined return, supporting records and the IRS notice showing the tax year |
How the rule works
Start by identifying the legal character of the payment, account, credit, deduction, benefit or loan. A marketing label does not control the tax result. Dates, ownership, business purpose, filing status, income limits, residency and documentation can turn a superficially similar situation into a different answer.
- The familiar three-year rule is an assessment limitation, not a command that every audit must finish exactly three years after filing.
- A more-than-25% omission of gross income can create a six-year assessment period under Section 6501(e).
- Fraudulent returns and unfiled returns generally remain open indefinitely.
- Written consents can extend an otherwise applicable assessment period.
- Property basis, loss carryovers and credit carryforwards require records older than the ordinary three-year window because they affect later open returns.
Practical example
A 2022 return was timely filed April 15, 2023. The ordinary assessment period generally runs three years from the filing/due-date rule. If the return omitted more than 25% of gross income, a six-year period may apply. If no valid return was filed, the ordinary clock may never start.
This example isolates the principal rule. It is not a complete return calculation: phaseouts, other credits, state conformity, related-party rules, passive-loss limits and prior-year carryovers may change the outcome.
Step-by-step checklist
- Identify the actual filing date and statutory due date.
- Determine whether a substantial omission or special disclosure rule applies.
- Keep property and carryover records through the later disposition or use year.
- Read any consent extension before signing.
- Track assessment and collection limitation dates separately.
Reconcile the result to the actual return, notice, lender disclosure or benefit statement before signing. Preserve the source documents, calculations and proof of submission; a software interview or account screen is not a substitute for evidence.
Records to keep
Keep the filed forms and schedules together with receipts, statements, contracts, account records and correspondence that establish amount, date, ownership and purpose. For an asset, credit or carryforward that affects later years, retain the origin-year worksheet through the final disposition or use year and the applicable limitation period.
Common mistakes to avoid
- Discarding basis records after three years while still owning the asset.
- Confusing audit selection with the ten-year collection period.
- Assuming a substitute return prepared by the IRS starts the taxpayer's filing statute.
Correct an issuer or agency error through the documented correction process rather than silently changing a reported amount. When the dollars are material, a notice deadline is close, or the facts involve more than one jurisdiction, obtain advice from a credentialed professional who can review the complete record.
Related NavajoTax guides
Continue with amended return audit risk, correspondence audit steps. These related pages explain connected rules, but the current official form or agency instruction controls the transaction you actually report.
Frequently asked questions
Can the IRS audit more than six years back?
Yes, particularly for fraud, no return and certain special international or listed-transaction rules.
Does filing late start the three-year period?
A valid late-filed return generally starts the ordinary assessment period from filing, subject to exceptions.
How long should property records be kept?
Keep them until the period expires for the return reporting the property's sale or other disposition.
Sources reviewed
Last reviewed: August 17, 2026. This article provides general educational information, not individualized tax, legal, investment, lending or benefits advice.