The IRS generally has three years to audit an Employee Retention Credit claim, but that window stretches to six years for credits claimed in the third and fourth quarters of 2021. The ERC statute of limitations runs from the deemed filing date of your quarterly Form 941, not from the day you actually filed it, and several exceptions can extend or entirely remove the deadline. Which rule applies to you depends on the quarter the credit covered and whether Congress lengthened the ordinary period for that quarter.
When the Clock Starts Running
Every statute of limitations needs a starting point. For the ERC, that starting point is the deemed filing date of the quarterly Form 941. Under a special rule for employment taxes, if you filed your Form 941 before April 15 of the year after the calendar year in question, the IRS treats the return as filed on that April 15.1Office of the Law Revision Counsel. 26 U.S. Code 6501 – Limitations on Assessment and Collection
So all four quarterly Forms 941 for 2020 are treated as filed on April 15, 2021, and all four for 2021 are treated as filed on April 15, 2022. The IRS’s clock to challenge the credit starts ticking from those dates, no matter when you mailed the return.2Internal Revenue Service. Instructions for Form 941-X
If you filed a Form 941-X later to claim the ERC retroactively, the assessment period for the original return still runs from the deemed filing date of the original Form 941. Amending does not restart the basic three-year clock, though it can bring additional scrutiny during whatever time remains.
IRS Assessment Deadlines by Quarter
Congress changed the rules partway through the ERC program, creating a patchwork of assessment deadlines that catches many employers off guard.
All Four Quarters of 2020
Every 2020 quarter follows the standard three-year assessment period. With a deemed filing date of April 15, 2021, the IRS’s window to challenge 2020 ERC claims closed on April 15, 2024.3Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection If you claimed the credit for 2020 wages and haven’t heard from the IRS, you’re generally in the clear unless one of the exceptions below applies.
First and Second Quarters of 2021
Q1 and Q2 of 2021 also follow the standard three-year rule. With a deemed filing date of April 15, 2022, the IRS’s assessment deadline was April 15, 2025.4Internal Revenue Service. Frequently Asked Questions About the Employee Retention Credit
Third and Fourth Quarters of 2021
This is where the timelines diverge sharply. Section 3134(l) of the Internal Revenue Code originally gave the IRS a five-year assessment window for credits claimed in Q3 and Q4 of 2021. The One Big Beautiful Bill Act extended that period to six years. With a deemed filing date of April 15, 2022, the IRS now has until roughly April 15, 2028 to audit and assess additional tax on Q3 and Q4 2021 ERC claims.
The longer deadline reflects Congress’s concern that claims from the tail end of the program were especially prone to error and fraud. Businesses that claimed the credit for Q3 or Q4 2021 wages face a meaningfully longer audit window than those with earlier claims.
The Taxpayer’s Filing Window Is a Separate Deadline
The employer’s deadline to file or amend an ERC claim runs on a different track from the IRS’s deadline to audit one. Under the general rule for refund claims, employers had three years from the deemed filing date to submit a Form 941-X.5Office of the Law Revision Counsel. 26 USC 6511 – Limitations on Credit or Refund The deadline for 2020 claims expired April 15, 2024, and the deadline for all 2021 quarters expired April 15, 2025.4Internal Revenue Service. Frequently Asked Questions About the Employee Retention Credit No new or amended ERC claims can be filed for any quarter.
The two deadlines create an important asymmetry. An employer who claimed the ERC for Q3 or Q4 of 2021 lost the ability to amend that claim in April 2025, but the IRS can still audit and challenge it until 2028. You could face an audit years from now with no ability to revise the claim on your own terms.
Erroneous Refund Lawsuits
Beyond the standard assessment process, the IRS has a separate legal tool for clawing back ERC refunds it already paid out. Under IRC Section 7405, the government can file a lawsuit to recover any tax refund paid in error.6Office of the Law Revision Counsel. 26 U.S. Code 7405 – Action for Recovery of Erroneous Refunds
Under IRC Section 6532(b), the government generally has two years from the date the refund was paid to bring the action. If the refund was induced by fraud or a material misrepresentation of fact, that window extends to five years. This is a backup mechanism: even when the ordinary assessment period is tight, an erroneous refund suit gives the government a separate route to recover money that was already sent out.
Exceptions That Extend or Eliminate the Deadline
The timelines above are the ordinary limits. Several statutory exceptions can push the deadline out further or remove it entirely.
- Fraud or willful evasion. If the IRS proves in court that a return was fraudulent or that the taxpayer willfully attempted to evade tax, there is no statute of limitations. The IRS can assess tax or pursue collection at any time.3Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
- No return filed. If a required employment tax return was never filed, the assessment period never starts. The IRS can act at any time.
- Substantial omission. If a taxpayer omits more than 25% of the gross income reported on a return, the IRS gets six years instead of three. This rule primarily targets income tax returns but could reach complex ERC situations involving employment tax returns.
- Consent to extend. The IRS and the taxpayer can mutually agree to extend the assessment period by signing Form 872. Taxpayers sometimes sign one during an audit to gather records or negotiate. The agreement must be executed before the original deadline expires.
- Tax Court petition. If the IRS issues a notice of deficiency, the three-year clock pauses. It stays paused from the day after the notice is mailed until 60 days after the Tax Court issues a final decision.7Internal Revenue Service. Time IRS Can Assess Tax
The fraud exception is the one that looms largest over ERC claims. The IRS has been explicit that it is pursuing criminal and civil fraud cases against businesses and promoters who filed bogus claims. For any employer whose claim was based on fabricated eligibility or inflated wage figures, the normal deadlines are irrelevant.
What a Successful IRS Challenge Costs
When the IRS disallows an ERC claim, the employer loses the credit and picks up penalties and interest that can dwarf the original refund.
Accuracy-Related Penalty
For claims disallowed due to negligence or a substantial understatement, the IRS imposes a penalty equal to 20% of the underpayment.8Office of the Law Revision Counsel. 26 U.S. Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments If the underpayment involved a gross valuation misstatement, that penalty doubles to 40%. Employers with legitimately mistaken claims most often see this penalty.
Civil Fraud Penalty
If any part of the underpayment is due to fraud, the penalty jumps to 75% of the fraudulent portion.9Office of the Law Revision Counsel. 26 U.S. Code 6663 – Imposition of Fraud Penalty The IRS bears the burden of proving fraud, but the volume of ERC mills that fabricated eligibility for clients leaves many claims exposed.
Interest
Interest accrues on the entire unpaid balance from the date the erroneous refund was issued. For the first quarter of 2026, the IRS underpayment rate is 7%, compounded daily. Large corporate underpayments carry a 9% rate.10Internal Revenue Service. Quarterly Interest Rates Because ERC refunds often went out years ago, the accumulated interest on a disallowed claim can be substantial before any penalty is added.
Criminal Exposure
In the most egregious cases, the IRS and Department of Justice pursue criminal charges. Tax evasion under 26 U.S.C. ยง 7201 carries up to five years in prison and fines of $100,000 for individuals or $500,000 for businesses. Wire fraud, mail fraud, and conspiracy charges can push potential prison time higher. The IRS has made ERC fraud a public enforcement priority, and criminal investigations are ongoing.
Where Your Exposure Stands Today
Work backward from your quarter. A 2020 claim is generally past the ordinary assessment deadline. A Q1 or Q2 2021 claim passed the ordinary deadline in April 2025. A Q3 or Q4 2021 claim remains open into 2028. Add the fraud exception, the possibility of an erroneous refund suit within two years of payment (five if fraud is alleged), and any Form 872 extension you may have signed. Those layers, not the base three-year rule, are what determine whether the IRS can still come back on your claim.