A mail audit, sometimes called a correspondence audit, is a common type of IRS tax audit conducted entirely through mail correspondence. When the IRS needs more information to verify your tax return — such as confirming reported income, deductions, or credits — they send an official letter requesting documents or clarification. Unlike office or field audits, a mail audit does not require a face-to-face meeting, making it less intrusive.
How Does a Mail Audit Begin?
You typically receive a letter from the IRS shortly after filing your tax return—often after you’ve already received your refund. The letter outlines specific parts of your tax return that the IRS wishes to review. Common IRS notices initiating mail audits include the CP2000 notice, which addresses discrepancies between what you reported and what payers reported to the IRS, or other types of IRS notices requesting further information.
The IRS uses mail audits to ensure taxpayers are reporting accurate income and claiming only eligible deductions and credits. These audits often stem from computer programs detecting irregularities or mismatches in your tax return data.
The Mail Audit Process
- Receiving the Notice: The IRS sends a letter explaining the areas under review and requests supporting documentation.
- Reviewing the Request: Carefully read the letter to understand exactly what documents or explanations the IRS seeks.
- Gathering Documentation: Collect records such as W-2s, 1099s, receipts, bank statements, or any paperwork substantiating your tax return claims.
- Responding Timely: Usually, you have 30 days from the notice date to respond. Provide clear explanations and copies of requested documents.
- IRS Review and Outcome: The IRS examines your response and either accepts it, proposes adjustments, or requests additional information. Most mail audits conclude with the IRS confirming the audit closure.
Common Reasons for Mail Audits
- Unreported Income: Income reported on forms like 1099-NEC or 1099-INT that doesn’t appear on your return.
- Large or Suspicious Deductions: Especially high charitable contributions, medical expenses, or education credits needing verification.
- Child Tax Credit Qualification: Ensuring eligibility criteria like residency and relationship are met.
- Business Expenses: Self-employed taxpayers may need to substantiate various deductions.
- Cryptocurrency Transactions: Increasing scrutiny on digital asset reporting increases mail audits in this area.
Who Can Be Targeted?
Any taxpayer can receive a mail audit notice. Audits are often triggered by:
- Income discrepancies between what you report and what third parties report to the IRS.
- Claims of unusually high deductions relative to income.
- Errors or omissions detected by IRS automated systems.
How to Effectively Respond
- Stay Calm and Act Quickly: Don’t ignore the notice; missing deadlines can result in penalties.
- Review Carefully: Understand exactly what is requested.
- Send Copies, Not Originals: Always keep your originals safe.
- Be Specific and Organized: Address each item raised with appropriate documentation.
- Avoid Volunteering Extra Information: Only send what the IRS asks for to avoid expanding the scope.
- Consider Professional Assistance: A CPA or Enrolled Agent can help if you feel unsure.
Common Misconceptions to Avoid
- Receiving a mail audit doesn’t mean wrongdoing—it can be random or a simple clarification.
- You usually won’t need to meet an IRS agent for mail audits.
- Ignoring IRS correspondence will lead to penalties and increased liabilities.
- Never send original documents.
FAQs
How long do mail audits take?
Typically weeks to a few months depending on response speed and complexity.
Can a mail audit become an in-person audit?
Rarely, but possible if issues cannot be resolved by mail.
What if I lack requested documents?
Explain to the IRS and provide alternative evidence if possible.
Disagree with findings?
You can appeal through the IRS Appeals Office or tax court.
Do I need a lawyer?
Most mail audits do not require an attorney, but you may want one for complex issues.
For more detailed information about audits and IRS notices, see our IRS Audit and IRS Notice articles.
References
- Internal Revenue Service, “Understanding Your IRS Notice or Letter,” accessed June 2025, IRS.gov.
- Investopedia, “IRS Audits: What to Do If You’re Audited,” accessed June 2025, Investopedia.
- NerdWallet, “IRS Correspondence Audit: What to Do If You Get a Letter,” accessed June 2025, NerdWallet.