What to Do If the IRS Audits You

Receiving an IRS audit letter is not the way anyone wants to end tax season. But an audit is not an accusation of fraud. It is a review. The IRS defines an audit as a review or examination of an organization's or individual's books, accounts, and financial records to ensure information reported on the tax return is correct according to the tax laws and to verify the reported amount of tax is correct.

In 2026, the IRS uses advanced algorithms and artificial intelligence to identify discrepancies, unusual patterns, or high-risk tax positions. The IRS had 126 active AI use cases as of June 2025, according to a GAO report published in March 2026, with 61% still in development. The IRS has described AI as "night-vision goggles" to detect tax evasion. AI can analyze patterns across millions of returns faster than any human examiner, flagging returns that deserve a second look.

The scale of IRS enforcement is larger than most people realize. In FY2025, the IRS closed 497,621 traditional audits recommending $26.8 billion in additional tax, according to Clarity Tax Relief's analysis of IRS enforcement data. But the automated programs reached far more people. The Automated Underreporter (CP2000) program closed 987,460 cases with $5.9 billion in assessments. The Automated Substitute for Return program closed 592,773 cases worth nearly $2.9 billion. Combined, the IRS made more than 2 million enforcement contacts in a single fiscal year.

The good news is that most audits are correspondence audits handled entirely by mail. Only a small percentage require in-person meetings. The key is knowing which type you face, responding within the deadline, and providing only what is asked. If you are searching for what to do if the IRS audits you, this guide covers the 4 types of audits, how the IRS selects returns, audit triggers in 2026, response deadlines, how to respond to each type, your rights, when to hire representation, and what happens after the audit.

The 4 Types of IRS Audits

Correspondence audit (most common, approximately 75% of individual audits)

Conducted entirely by mail. Focuses on 1 to 2 specific line items. The typical notice is a CP2000 or Letter 566. The average deficiency runs $5,000 to $15,000. Duration is 3 to 6 months. The response deadline is 30 days from the notice date, not the receipt date. Common targets include unreported 1099 income, charitable contribution substantiation, and home office deductions.

Office audit (moderate complexity)

Conducted in person at an IRS Taxpayer Assistance Center. Covers 3 to 5 specific issues. The typical notice is Letter 3572. The average deficiency runs $15,000 to $50,000. Duration is 6 to 12 months. The examiner is a Tax Compliance Officer. Common targets include business income and expenses, rental property depreciation, and multiple years.

Field audit (high stakes)

A Revenue Agent visits your home or business. Full return review, often covering multiple years. The typical notice is Letter 2205-A for individuals or 2205-B for businesses. The average deficiency is $100,000 or more. Duration is 12 to 24 months. The response deadline is 10 business days to schedule the initial meeting, the shortest deadline of any audit type. The examiner is a Revenue Agent, typically a CPA or enrolled agent with years of IRS training. Common targets include high-income taxpayers ($200,000+), businesses with complex structures, and suspected substantial underreporting.

TCMP or NRP audit (rare, research-based)

Random, line-by-line examination of the entire return. Not deficiency-driven. Used for research and compliance measurement. Duration is 12 to 18 months. These are very rare.

How the IRS Selects Returns

Selection methods

1. Document matching: IRS computers compare W-2s, 1099s, K-1s against your return. Mismatches trigger CP2000 notices automatically. This is the highest-volume enforcement tool by far.
2. Statistical analysis: returns with deductions outside statistical norms for your income bracket.
3. AI-identified anomalies: patterns across millions of returns that suggest underreporting. The IRS is training AI models on current return data rather than relying solely on historical examination results.
4. Related examinations: if your business partner or investor is audited, you may be too.
5. Random selection: rare, used for research (TCMP or NRP).

How far back can the IRS go?

Generally includes returns filed within the last 3 years. If a substantial error is identified, the IRS may add additional years. Usually the IRS does not go back more than 6 years. For more details, see the IRS page on audits.

Audit Triggers in 2026

Top triggers

Unreported income is the number one trigger. The IRS receives copies of every W-2, 1099-NEC, 1099-K, 1099-INT, 1099-DIV, and K-1 issued to you. Their computers automatically match these against your tax return. If you report $85,000 in income but your 1099s total $92,000, you will get a CP2000 notice.

Home office deduction triggers audits more frequently than almost any other Schedule C item. The IRS knows most taxpayers do not meet the strict "exclusive and regular use" requirement.

Large charitable contributions relative to income. Giving $20,000 on $60,000 income triggers scrutiny.

Business expenses that are high relative to revenue, especially for cash businesses.

Foreign accounts and FATCA reporting. The IRS receives data from foreign governments.

Cryptocurrency. The IRS has stepped up enforcement on unreported crypto transactions.

How to Respond

Correspondence audit response

1. Read the notice carefully. Identify the tax year, proposed adjustments, and documents requested.
2. Gather only the requested documents (receipts, bank statements, mileage logs).
3. Send copies, never originals. The IRS will not return documents.
4. Respond within 30 days. If you need more time, request a 30-day extension, which is automatically granted for correspondence audits.
5. If penalties are proposed (accuracy-related under IRC Section 6662: 20% of understatement, up to 40% for gross valuation misstatements or 75% for fraud), engage a tax professional before responding.

Office audit response

1. Bring only the documents requested in the notice.
2. Do not volunteer additional information.
3. If the examiner asks about issues not in the original notice, you have the right to end the meeting and consult a tax advisor.
4. Consider hiring a CPA or enrolled agent to accompany you.

Field audit response

1. Hire professional representation immediately (CPA, enrolled agent, or tax attorney).
2. Do not handle a field audit yourself. The stakes are too high and the process too complex.
3. The first interview is the most consequential meeting. Answers shape the entire examination.
4. The 10-business-day deadline to schedule the initial meeting is already running when you receive the letter.

Your Rights During an Audit

Taxpayer rights

• Right to representation: you may have an attorney, CPA, or enrolled agent represent you. File Form 2848 (Power of Attorney).
• Right to appeal: if you disagree with the audit findings, you can appeal to the IRS Independent Office of Appeals.
• Right to record: you may make an audio recording of the examination interview. Notify the examiner at least 10 days in advance.
• Right to extension: you can request additional time to respond.
• Right to claim hardship: if collection would create economic hardship.

See IRS Publication 5146 for the full examination process and your rights.

The 90-day rule

If you receive a Notice of Deficiency (CP3219A) by certified mail, you have 90 days to petition the U.S. Tax Court. The IRS cannot extend this 90-day deadline. You can continue working with the IRS to resolve the matter, but the Tax Court petition preserves your rights.

What Happens After the Audit

Three possible outcomes

1. No change: the IRS accepts your return as filed. No additional tax owed.
2. Agreed: the IRS proposes changes, you agree. You sign the audit report and pay any additional tax, penalties, and interest.
3. Disagreed: the IRS proposes changes, you disagree. You can appeal to the IRS Independent Office of Appeals or petition the U.S. Tax Court.

Penalties

The accuracy-related penalty under IRC Section 6662 is 20% of the underpayment due to negligence or substantial understatement. It can escalate to 40% for gross valuation misstatements or 75% for fraud. Interest accrues on both the additional tax and penalties from the original due date of the return.

IRS Audit Types: What to Expect

Three Real Audit Scenarios

Example 1: CP2000 correspondence audit, freelance graphic designer

A freelance graphic designer receives a CP2000 notice. The IRS says she reported $72,000 in income but her 1099-NEC forms total $84,500. The difference is a $12,500 payment from a client who sent a 1099 to her old address. The proposed additional tax is $2,750 (22% bracket) plus a $550 accuracy-related penalty (20% of $2,750) plus interest. Total owed: approximately $3,500.

Response: she gathers the 1099 she missed, acknowledges the error, and agrees to the adjustment. She requests first-time penalty abatement because she has a clean compliance history (3 years of timely filed returns, no prior penalties). The penalty is waived. Total paid: $2,750 plus interest.

The lesson: most correspondence audits are simple document-matching issues. Respond within 30 days. Acknowledge errors. Request first-time penalty abatement. The IRS is generally reasonable with taxpayers who respond promptly and honestly.

Example 2: Office audit, small business owner with Schedule C

A small business owner receives Letter 3572 for an office audit. The audit covers his Schedule C for 2024: $180,000 in revenue, $95,000 in expenses (including $30,000 in vehicle expenses, $15,000 in meals and entertainment, and $12,000 in home office). The IRS questions these three categories.

He hires a CPA to represent him. The CPA reviews his records. Vehicle expenses are documented with a mileage log: 14,000 business miles multiplied by $0.67 per mile equals $9,380, but he claimed $30,000. Meals are partially documented: receipts for $8,000, not $15,000. Home office meets the exclusive use requirement (a dedicated 200 square foot room).

Outcome: vehicle expenses reduced from $30,000 to $9,380. Meals reduced from $15,000 to $8,000 (and 50% deductible equals $4,000). Home office sustained. Additional tax: approximately $5,200 (22% bracket on $23,620 in disallowed deductions). Penalty: $1,040 (20% accuracy-related). Total: approximately $6,240 plus interest.

The lesson: office audits focus on specific issues. Have documentation for every deduction. If your records do not support the claimed amount, the IRS will disallow the excess. A CPA can negotiate which deductions to sustain and which to concede.

Example 3: Field audit, business owner with $2M revenue

A business owner with $2 million in annual revenue receives Letter 2205-B for a field audit. The audit covers 2022 through 2024 corporate returns. The Revenue Agent wants to review books, income, expenses, bank deposits, and inventory.

The business owner hires a tax attorney immediately. The attorney handles all communication with the Revenue Agent. The initial interview is conducted with the attorney present, who limits the scope of questions to the tax returns under examination.

The audit reveals $45,000 in personal expenses run through the business (vehicle leases for family members, personal travel). The IRS proposes $45,000 in additional income, $9,900 in additional tax (21% corporate rate), $1,980 accuracy-related penalty, plus interest. Total: approximately $12,500.

The attorney negotiates. Some of the vehicle expenses are legitimate business use (60% business, 40% personal). Final adjustment: $18,000 personal expenses. Tax: $3,780. Penalty waived (first-time, good faith cooperation). Total: $3,780 plus interest.

The lesson: field audits are serious. Hire representation immediately. The attorney limited the scope of the initial interview, which shaped the entire examination. Without representation, the business owner might have answered questions broadly, expanding the audit scope. With representation, the audit was contained.

Common Mistakes

Ignoring the notice. The IRS will complete the audit without you and propose changes. You lose the opportunity to defend your return.

Missing the deadline. Correspondence audits give 30 days. Field audits give 10 business days. If you need more time, request an extension. Do not let the deadline pass.

Sending original documents. The IRS will not return them. Send copies only.

Volunteering extra information. Provide only what is requested. Extra information can expand the audit scope.

Not hiring representation for office and field audits. A CPA or tax attorney knows what to provide and what not to provide. They know how to interact with IRS agents.

Panicking. Most audits are correspondence audits resolved with a few receipts. Take a deep breath. It may not be as bad as you think.

Not requesting first-time penalty abatement. If you have a clean compliance history (3 years of timely filed returns, no prior penalties), the IRS may waive the first accuracy-related penalty.

Not understanding the 90-day Tax Court deadline. If you receive a Notice of Deficiency, you have 90 days to petition the Tax Court. This deadline cannot be extended.

Guessing on missing documents. If you do not have a receipt, do not guess. Say you do not have it. Guessing can be treated as fraud.

Not keeping good records. If you have kept good records, there is no reason to panic. It is usually resolved after a few interactions and once you share a receipt or two. For staying on track financially after an audit, read our guide on how to set up automatic investing.

Respond Now, Not Later

An IRS audit is a review, not an accusation. In 2026, the IRS uses AI to flag returns, with 126 active AI use cases as of June 2025. The 4 types are correspondence (approximately 75% of audits, $5,000 to $15,000, by mail, 30-day deadline), office ($15,000 to $50,000, in person, 3 to 5 issues), field ($100,000+, Revenue Agent at your business, 10 business day deadline), and TCMP or NRP (random research audit). The IRS selects returns through document matching (W-2 and 1099 mismatches trigger CP2000 automatically), statistical analysis, AI anomalies, and related examinations. The IRS generally audits returns from the last 3 years, up to 6 for substantial errors.

Top triggers: unreported income, home office deductions, large charitable contributions, business expenses, foreign accounts, cryptocurrency. Response: read the notice, gather only requested documents, send copies, meet the deadline, do not volunteer extra information. Hire representation for office and field audits. Your rights: representation (Form 2848), appeal, recording, extension. If you receive a Notice of Deficiency, you have 90 days to petition the Tax Court. Outcomes: no change, agreed, or disagreed. Accuracy-related penalty: 20% of underpayment, up to 75% for fraud.

In FY2025, the IRS closed 497,621 traditional audits and 987,460 CP2000 cases. The automated programs dwarf traditional audits because a computer does nearly all of it. The IRS workforce was cut roughly 27% in 2025, but the automated matching software did not get laid off. Matching, notices, and escalation continue at machine speed.

Do three things if you receive an IRS audit notice. Read the notice immediately. Identify the audit type (correspondence, office, or field) and the response deadline. Gather only the documents requested. Make copies. Do not send originals. If it is an office or field audit, hire a CPA or tax attorney before responding. If it is a correspondence audit and you have the documents, respond within 30 days. For handling tax debt that may result from the audit, read our guide on what to do if your business fails and you owe taxes. For broader financial recovery, read our guide on what to do if you lose everything financially. For rebuilding your financial plan after an audit, read our guide on how to set financial goals that align with what you actually care about. For understanding how tax brackets interact with inflation, read our guide on what is inflation really.

The single most important thing you can do when you receive an audit notice is respond. Not next month. Not next week. Now. The IRS is not your enemy. They are doing their job. Your job is to demonstrate that your return is accurate. If it is, the audit ends with no change. If it is not, your job is to minimize the damage. Either way, the process starts with reading the notice and responding on time.

This post is for informational purposes only and does not constitute tax or legal advice. IRS audit procedures and penalty amounts may change. Consult a qualified CPA, enrolled agent, or tax attorney before responding to an IRS audit notice.