What Is IRS Error Code 428 and How Does It Affect Your Tax Return?

Taxpayers sometimes encounter IRS error codes when filing their returns, which indicate issues requiring resolution before processing can be completed. One such issue is IRS Error Code 428, which often requires additional verification or documentation.

Understanding this code and how to address it promptly can help prevent delays in receiving tax refunds or resolving discrepancies.

Potential Filing Errors That Trigger This Code

IRS Error Code 428 typically results from discrepancies in reported information, particularly mismatched Social Security numbers. This can occur if a taxpayer enters an SSN incorrectly or if the IRS database does not match the provided details. A common cause is a name change due to marriage or divorce that has not been updated with the Social Security Administration.

Another frequent issue is conflicting dependent claims. If multiple taxpayers attempt to claim the same dependent—often in cases of divorced parents—the IRS may flag the return. The parent who does not meet the IRS’s custodial parent rule, outlined in Publication 501, may trigger this error.

Errors in tax credits and deductions can also lead to this issue. Claiming the Earned Income Tax Credit (EITC) without meeting eligibility requirements can result in rejection. Similarly, incorrect reporting of self-employment income or business expenses on a Schedule C can raise red flags, especially if deductions appear excessive compared to reported earnings.

Verification of Reported Income

This error code often signals a mismatch between the income reported on a tax return and the information the IRS has on file. This typically happens when taxpayers receive income from multiple sources—such as wages, freelance work, rental properties, or investments—and fail to report all of it accurately. The IRS cross-references tax returns with data from employers, financial institutions, and other third parties using forms like W-2s and 1099s.

Unreported income from side jobs or contract work is a common issue. Businesses that hire independent contractors must file Form 1099-NEC for nonemployee compensation exceeding $600. If a taxpayer omits this income, the IRS detects the discrepancy. Investment income reported on Form 1099-DIV or 1099-INT can also cause issues if dividends, interest, or capital gains are not included.

Employer reporting errors can also trigger income verification. If an employer submits incorrect wage data on a W-2 or fails to file it on time, the IRS may not have accurate information to match against the taxpayer’s return. In such cases, additional documentation, such as pay stubs or employer-issued earnings statements, may be required.

Submitting Additional Documents

When the IRS flags a tax return with Error Code 428, supporting documentation may be needed. If a filer claims the Child Tax Credit (CTC) or the American Opportunity Credit (AOC), the IRS may request school records, birth certificates, or Form 1098-T to confirm eligibility. Ensuring these documents match the information submitted on the return can prevent further complications.

For self-employed individuals, the IRS may request bank statements, invoices, or receipts to verify reported figures on a Schedule C. If a taxpayer claims a home office deduction, providing utility bills, lease agreements, or photographs of the workspace can help establish legitimacy. The IRS closely examines deductions that seem disproportionate to income, so keeping well-organized records can expedite the review process.

For rental income, the IRS may seek lease agreements, maintenance records, or mortgage interest statements to confirm reported earnings and deductions. Depreciation calculations must follow IRS guidelines under the Modified Accelerated Cost Recovery System (MACRS), and misclassified expenses—such as repairs versus capital improvements—can lead to further inquiries.

Communication With the IRS

Addressing IRS Error Code 428 requires timely communication with the agency to avoid penalties or adjustments. Taxpayers typically receive a notice, such as a CP2000, outlining the issue and providing a deadline for response. Ignoring these notices can lead to penalties, adjustments to the return, or a formal tax assessment. Responding within the specified timeframe helps prevent additional interest or failure-to-pay penalties, which accrue at a rate of 0.5% per month.

Providing a clear and well-documented response is essential. If the IRS requests clarification, submitting a written explanation along with necessary forms—such as Form 8862 for taxpayers reapplying for disallowed credits—can help expedite processing. When mailing documents, using certified mail with return receipt requested ensures proof of submission. For those opting for electronic communication, the IRS Secure Messaging system, available for certain cases through the Taxpayer Digital Communications platform, may be a faster alternative.

Refund Delays and Next Steps

When IRS Error Code 428 appears on a tax return, processing delays are likely. The IRS typically places a hold on the refund until the discrepancy is resolved, which can extend the standard processing time beyond the usual 21-day window for electronically filed returns. If additional verification is required, the delay can stretch to several weeks or even months, especially during peak tax season.

Taxpayers can monitor their refund status using the IRS “Where’s My Refund?” tool or by checking their IRS Online Account. If the return is under review, the status may indicate “processing” for an extended period. In some cases, the IRS may issue a partial refund while withholding the disputed portion until verification is complete. If a taxpayer believes the delay is excessive, contacting the IRS directly or seeking assistance from the Taxpayer Advocate Service (TAS) may help expedite resolution.