What Happens If I Put the Wrong EIN on My Tax Return?

Entering the wrong Employer Identification Number (EIN) on your tax return can lead to processing delays, errors, or IRS correspondence. Since the EIN identifies businesses for tax purposes, a mistake can cause mismatches in records.

Immediate Filing Issues

An incorrect EIN can prevent the IRS from processing a tax return if it does not match the agency’s records. The IRS cross-references EINs to verify that the return belongs to the correct entity. If the number is invalid or assigned to another business, the return may be rejected.

Even if accepted, an incorrect EIN can create discrepancies, especially for businesses making estimated tax payments. If the EIN on the return does not match the one used for those payments, the IRS may not properly credit them, leading to underpayment notices or penalties.

For businesses filing information returns like Forms 1099 or W-2, an incorrect EIN can cause reporting mismatches. If the IRS cannot reconcile the EIN on the tax return with third-party filings, it may trigger an inquiry. This is particularly relevant for corporations and partnerships, where EIN accuracy links shareholder or partner income to individual tax returns.

Correcting the Submitted Return

Fixing an incorrect EIN depends on when the error is discovered. If caught before processing, an amended return may not be necessary. If the return has been accepted, corrections must be made using Form 1040-X for individuals, Form 1120-X for corporations, or Form 1065-X for partnerships. S corporations may need to file an administrative adjustment request (AAR) under Bipartisan Budget Act rules.

If the incorrect EIN was also used on payroll tax filings like Form 941 or Form 940, or on information returns such as Form 1099-MISC, those may need to be amended to prevent inconsistencies. Mismatched EINs across filings can lead to IRS scrutiny, especially if reported income does not align with employer or payer records.

Timely corrections help avoid complications. If the EIN error resulted in misapplied payments, contacting the IRS Business & Specialty Tax Line at 800-829-4933 can help resolve allocation issues. If the mistake affects state tax filings, separate amendments may be required, as some states update records automatically while others require formal corrections.

Potential Impact on Refund Timing

Errors in tax filings can delay refunds, especially if the IRS must manually review the return. If an incorrect EIN is detected, the return may be flagged for additional scrutiny, shifting it from standard electronic processing to a more time-intensive review. This can extend processing beyond the typical 21-day window for e-filed returns or six to eight weeks for paper filings.

Returns requiring manual handling are often routed to the IRS’s Error Resolution System, where an examiner verifies the EIN against business records. This process can take weeks, depending on workload and complexity. If additional documentation is needed, such as proof of the correct EIN, the IRS may issue a notice requesting clarification. Responding promptly can help avoid further delays.

If an incorrect EIN causes a mismatch with reported income, the IRS may need to reconcile the discrepancy before issuing a refund. This is particularly relevant for returns linked to third-party filings, such as W-2s or 1099s. If the IRS cannot verify reported income due to an EIN error, the refund may be held until the issue is resolved.

Verification Requests from Tax Authorities

If the IRS detects an EIN inconsistency, it may initiate a verification process. This often begins with a CP215 or CP267 notice, informing businesses or individuals that an issue requires further review. The IRS may request documentation, such as a copy of the EIN assignment letter or prior-year tax returns, to confirm the correct entity identifier. Failure to respond within the specified timeframe can escalate the matter, potentially leading to enforcement actions or account freezes.

Beyond written correspondence, the IRS may conduct compliance checks to ensure the entity is properly registered. If the incorrect EIN is tied to payroll tax filings, the agency might initiate a Trust Fund Recovery Penalty investigation, holding responsible individuals liable for unpaid employment taxes. Discrepancies involving excise or corporate income taxes could also trigger an examination, allowing the IRS to summon records, interview officers, or conduct field audits.

Businesses operating in multiple states should be aware that state tax agencies may independently verify EINs to reconcile sales or franchise tax obligations. If discrepancies are found, state authorities may request additional documentation or impose penalties for incorrect filings.