The IRS generally has three years from the date you file to audit your return and assess more tax. That window doubles to six years if you left off a large chunk of income, and it never closes at all if you filed a fraudulent return or didn’t file one in the first place. So the honest answer to how far back the IRS can audit you is: usually three years, sometimes six, and in a few situations, forever. Actual audit rates are low — the IRS examined about 0.3% of individual returns for tax year 2022 — but the deadlines still matter, because they tell you how long the agency can come knocking and how long you need to keep your records.
The Three-Year Default
For most taxpayers, the IRS has three years to audit a return and assess additional tax. This is the standard rule, sometimes called the Assessment Statute Expiration Date.1Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
The clock starts on the later of two dates: the day you actually file, or the return’s original due date. File your 2025 return early on February 20, 2026, and the clock still starts April 15, 2026. File late without an extension on July 10, and the clock starts July 10. If you got an extension to October 15 and filed September 3, the three years run from September 3. Filing early never shortens the window. Filing late always pushes it out.2Internal Revenue Service. Time IRS Can Assess Tax
When It Stretches to Six Years
Two situations involving unreported income double the standard window to six years.
The first is a substantial omission of income. If you leave off an amount that exceeds 25% of the gross income you did report, the six-year period applies. The threshold is measured against what your return showed, not what you should have reported. A return showing $100,000 in gross income when you actually earned $130,000 means a $30,000 omission — 30% of the reported figure, past the 25% line.1Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
Disclosure gets you out of this rule. If you described the omitted amount on your return or in an attached statement clearly enough for the IRS to identify it, that amount doesn’t count toward the 25% test, even if the agency later disagrees with how you treated it.3Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
The second trigger involves foreign financial assets. If you fail to report more than $5,000 of income tied to assets that should have been disclosed on Form 8938, the six-year window applies regardless of the 25% test. The $5,000 threshold looks at all your specified foreign financial assets, including ones that fall below the normal Form 8938 reporting threshold.4Internal Revenue Service. Instructions for Form 8938
When There’s No Deadline at All
In a handful of serious situations, the statute of limitations never expires. The IRS can audit and assess tax for the year in question at any point in the future.
Fraudulent returns. A return that is false or fraudulent with the intent to evade tax has no assessment deadline. Fraud is a high bar for the IRS to prove; the agency must show willful conduct, not carelessness. When it does, the window stays open indefinitely.2Internal Revenue Service. Time IRS Can Assess Tax
Returns you never filed. If you don’t file for a given year, the three-year clock never starts. The IRS can assess tax for that year indefinitely. This is why filing a late return is almost always better than filing nothing. A late return at least starts the clock.2Internal Revenue Service. Time IRS Can Assess Tax
Undisclosed gifts. Gift tax returns follow a similar rule. If you were required to file Form 709 and didn’t, or you filed but failed to adequately disclose a gift, the IRS can assess gift tax on that transfer at any time. Adequate disclosure means describing the property, the relationship between you and the recipient, and the method used to determine fair market value. Without that level of detail, the clock never starts.3Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
Situations That Shift or Pause the Clock
A few less common rules can extend or suspend the standard window.
Worthless Securities and Bad Debts
Claims for a worthless security or a bad debt get a seven-year window from the return’s due date, four years longer than the usual period. The IRS gets a matching seven years to review the claim. The extended period reflects how hard it can be to pinpoint the year a security became worthless.5Internal Revenue Service. How Long Should I Keep Records
Voluntary Extensions
You and the IRS can agree to extend the assessment deadline using Form 872, Consent to Extend the Time to Assess Tax. This usually comes up during a complex audit when either side needs more time. Signing is voluntary. The form itself states you can refuse or limit the extension to specific issues or a specific period.6Internal Revenue Service. Form 872 – Consent to Extend the Time to Assess Tax
Missing Form 8938
Skipping Form 8938 when it was required does more than trigger the six-year rule. It can keep your entire return open past the normal deadline. If you never file the form, the statute for that tax year stays open until three years after you eventually file it, and the IRS can examine the whole return, not just the foreign asset items.4Internal Revenue Service. Instructions for Form 8938
Notice of Deficiency
When the IRS sends a formal Notice of Deficiency, the assessment clock pauses. It stays paused for the 90-day period you have to petition the Tax Court (150 days if you’re outside the United States), plus 60 days after that. If you petition the court, the clock stays paused until the case is decided.
Assessment Is Not the Same as Collection
The deadlines above govern how long the IRS has to look at your return and decide what you owe. Once the tax is assessed, a separate 10-year clock starts for actually collecting it. This Collection Statute Expiration Date gives the IRS a decade from the assessment date to pursue payment through levies, liens, and other tools.7Internal Revenue Service. Time IRS Can Collect Tax
The distinction matters. Even after the audit window closes and the IRS can no longer increase what you owe, the agency may still have years left to collect a balance that was already assessed. Several common actions pause that 10-year clock:
- Requesting an installment agreement: suspended while the IRS reviews, plus 30 days if the request is withdrawn, rejected, or termination is proposed.
- Submitting an offer in compromise: paused during review and through any appeal of a rejection.
- Filing for bankruptcy: suspended from the petition date until the case is discharged, dismissed, or closed, plus six more months.
- Living outside the United States for six months or more continuously: generally suspended for that time.
Each pause effectively adds time. Taxpayers sometimes extend the collection window by years without realizing it, through repeated installment agreement requests or offers in compromise.7Internal Revenue Service. Time IRS Can Collect Tax
How Long to Keep Your Records
Your record retention should match the longest audit window that could apply. The IRS’s guidance:
- Three years for most taxpayers with straightforward returns.
- Six years if you might have underreported income by more than 25% of what your return showed.
- Seven years if you claimed a worthless securities loss or a bad debt deduction.
- Indefinitely if you filed a fraudulent return or didn’t file at all.
- At least four years for employment tax records, measured from the date the tax became due or was paid, whichever is later.
Property records need longer horizons. Keep everything tied to real estate or other assets until the statute of limitations runs on the year you sell or dispose of the property. Purchase price, improvement costs, and depreciation all shape the gain or loss at sale, so records for a long-held home or rental may need to stretch back decades. For property received in a tax-free exchange, keep records for both the old and the new asset until you eventually dispose of the new one.5Internal Revenue Service. How Long Should I Keep Records
State Audits Follow Their Own Rules
Everything above is federal. Each state with an income tax sets its own audit statute of limitations, generally somewhere between three and six years, with different triggers for extensions and different fraud rules. Some states tie their window to the federal statute, so a federal extension automatically extends the state’s window too. Check your state’s department of revenue for the rules that apply to you.