How Long the IRS Can Audit Your Tax Return

The IRS has three years from the date you file to audit most tax returns, but longer in certain situations

The standard statute of limitations for an IRS audit is three years from the date you file your return or the return's due date, whichever is later. This means the IRS cannot examine your return after that window closes. However, this three-year window is not absolute — it extends to six years if you underreport income by 25 percent or more, and there is no time limit at all if the IRS suspects fraud or if you did not file a return.

Understanding these timelines matters because they affect how long you need to keep records, when you can stop worrying about a particular tax year, and what to do if the IRS contacts you years after you filed. The rules are the same whether you filed on time or late, though the clock starts from different points depending on your situation.

Key Takeaways

The IRS can audit returns filed within the past three years for most taxpayers, measured from the filing date or due date, whichever is later.
The audit window extends to six years if you underreported income by 25 percent or more on your return.
There is no time limit for audits involving fraud or returns that were never filed.
You should keep tax records for at least three years, and six years if you have significant income underreporting.
If the IRS contacts you about a return from more than three years ago, ask to see the written notice explaining why the longer statute applies.

The three-year standard window and how it is measured

For most returns, the three-year window begins on the later of two dates: the date you actually filed your return, or April 15 of the year after the tax year in question. If you filed your 2022 return on March 1, 2023, the clock starts March 1, 2023. If you filed it on June 15, 2023, the clock still starts April 15, 2023 (the original due date), because that is the later date. Once three years pass from whichever date applies, the IRS cannot open an audit on that return.

This three-year period applies to most individual returns and covers the most common audit triggers: math errors, missing income, inflated deductions, and other discrepancies the IRS catches through matching documents (like W-2s and 1099s) or through random selection. If you filed early, you do not get a shorter window — the IRS still has until three years after the original due date.

When the IRS gets six years instead of three

If you underreported your gross income by 25 percent or more, the statute of limitations extends from three years to six years. "Underreported" means the income you reported on your return was significantly less than what you actually earned. The IRS measures this as a percentage of the income you did report, not the income you should have reported.

For example, if you reported $40,000 in income but actually earned $60,000, you underreported by 33 percent ($20,000 divided by $60,000). That triggers the six-year window. If you reported $40,000 and earned $50,000, you underreported by 20 percent, which stays within the three-year window. The IRS does not have to prove fraud to use the six-year rule — substantial underreporting alone is enough.

No time limit for fraud or unfiled returns

The IRS has no statute of limitations if it suspects tax fraud — intentional wrongdoing to evade taxes. Fraud is different from a mistake or even negligence. The IRS must prove you acted with intent to deceive, which is a high bar, but if they make that case, they can audit returns from decades ago. Fraud audits are rare and usually involve criminal investigation, not just a civil examination.

Similarly, if you never filed a return for a particular year, the IRS can assess taxes and penalties at any time. There is no statute of limitations on unfiled returns because the clock never starts — you did not trigger the filing deadline by submitting a return. The IRS can go back many years and demand payment plus interest and penalties.

What happens when the IRS contacts you about an old return

If the IRS sends you a notice about a return outside the normal three-year window, the notice should explain why the longer statute applies. It might say the six-year rule applies because of substantial underreporting, or it might reference fraud or an unfiled return. Read the notice carefully and keep it — it is your documentation of the reason.

If you receive an audit notice and believe the IRS is outside the statute of limitations, you can raise that as a defense. You do not have to prove the statute has run; the IRS must prove it has not. If you are unsure whether the notice is valid, you can contact a tax professional or the IRS directly to ask about the timeline. The IRS will provide the calculation if you ask.

How long to keep your tax records

The IRS recommends keeping tax records for at least three years after you file, since that covers the standard audit window. This includes your return itself, receipts, invoices, bank statements, cancelled checks, and any documents you used to support deductions or income figures. If you claim a loss or have substantial underreporting, keep records for six years.

For certain records — like those related to home purchases, retirement accounts, or business assets — you may need to keep them longer than six years because they affect future returns. A tax professional can advise on your specific situation, but three to six years is the baseline for most taxpayers.

Frequently Asked Questions

Can the IRS audit me for a return I filed 10 years ago?

Only if fraud is involved, you never filed that return, or you substantially underreported income and the IRS discovered it within the six-year window. For a standard return with no fraud or major underreporting, the IRS cannot audit returns older than three years from the filing date.

Does filing an amended return restart the statute of limitations?

Filing an amended return does not restart the three-year clock on the original return. However, if you amend a return to report additional income, the IRS has three years from the date you file the amendment to audit that amendment. The original return's statute continues to run independently.

What if I filed my return late — does that change the timeline?

No. The statute of limitations runs from the later of your actual filing date or the original due date (usually April 15). Filing late does not shorten or lengthen the window — the IRS still gets three years from one of those two dates.

How do I know if the IRS is still within the statute of limitations for my return?

Count three years forward from the date you filed or the return's due date, whichever is later. If that date has passed, the IRS is outside the standard window. If you received an audit notice claiming a longer period applies, the notice should explain the reason — ask the IRS to clarify if it does not.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.