IRS Audit: What to Expect

Not all audits are equal in scope or severity. The IRS uses three primary audit formats, each with different implications.

Audit Type	How It's Conducted	Scope	Frequency
Correspondence Audit	By mail only	Narrow — one or two issues	Most common (~75% of audits)
Office Audit	In-person at IRS office	Broader — several line items	Less common
Field Audit	IRS agent visits your home or business	Comprehensive	Rare; often for businesses
TCMP / Research Audit	Randomly selected; fully verified	Every line of the return	Very rare

A correspondence audit is the least alarming — the IRS simply asks for documentation to support a specific item (e.g., charitable contribution receipts or proof of a business expense). Responding promptly and completely usually resolves these within a few months.

The IRS uses a Discriminant Information Function (DIF) scoring system to rank returns for audit potential. Returns with scores that deviate significantly from the statistical norm for that income level are more likely to be selected. Common triggers include:

• Large charitable deductions relative to income — particularly non-cash donations over $500 (requiring Form 8283).
• Schedule C losses — especially recurring losses that look like a hobby rather than a business, or unusually high expense ratios.
• Home office deduction — must be exclusively and regularly used for business; a room that doubles as a guest bedroom doesn't qualify.
• Income mismatches — if a 1099 or W-2 received by the IRS doesn't match what you reported on your return.
• High income — audit rates for returns with income above $1 million are meaningfully higher than average.
• Math errors or missing forms — these trigger automatic notices, not full audits.

Warning: Crypto transactions remain a high-audit-risk area. The IRS now asks explicitly about virtual currency on Form 1040. Unreported transactions from exchanges that have provided 1099s to the IRS are easily identified.

The IRS Taxpayer Bill of Rights guarantees specific protections throughout the audit process. Understanding these rights helps you respond appropriately without over-disclosing.

• Right to representation: You may have a CPA, enrolled agent, or attorney represent you. You are not required to speak directly with an IRS agent.
• Right to know why: The IRS must explain why it is auditing you and what documentation it needs.
• Right to appeal: If you disagree with the audit findings, you can appeal to the IRS Independent Office of Appeals — a separate, impartial body.
• Right to finality: The IRS generally cannot audit the same tax year twice after it has been closed.
• Right to privacy: The IRS can only request information relevant to the specific items under examination.

Tip: Never expand the scope of information you provide beyond what was specifically requested. Volunteering additional information about unrelated items can open new lines of inquiry.

All IRS audit notices arrive by U.S. mail — the IRS does not initiate audits by phone, email, or social media. If you receive a phone call claiming to be the IRS, it is a scam.

Steps to take upon receiving a notice:

• Read it carefully and identify the exact tax year and items in question.
• Note the response deadline — typically 30 to 60 days. Missing it can result in automatic assessment of the amount the IRS proposes.
• Gather all supporting documents for the items questioned: bank statements, receipts, mileage logs, and third-party letters.
• Consider hiring a CPA or enrolled agent before responding, especially for office or field audits.

IRS Notice	What It Means
CP2000	Income mismatch — IRS proposes additional tax based on third-party data
Letter 2205	Notification that your return was selected for examination
Letter 525	Proposed changes after correspondence audit
Letter 531	Notice of deficiency — you have 90 days to petition Tax Court

Good recordkeeping is the best audit defense. The IRS generally has 3 years to audit a return from the filing date, extended to 6 years if income was understated by 25% or more, and indefinitely if fraud is involved.

• Keep all tax-related documents for at least 7 years to be safe — W-2s, 1099s, receipts, mileage logs, and brokerage statements.
• For business use of vehicles, maintain a contemporaneous mileage log with date, destination, purpose, and miles — reconstructed logs are less credible.
• Ensure all income reported on 1099s, K-1s, and W-2s is fully accounted for on your return.
• For charitable contributions over $250, obtain a written acknowledgment from the organization.

Tip: E-filing reduces math and transcription errors, which are the most common triggers for IRS notices. Returns filed electronically also have lower overall audit rates than paper-filed returns.