An IRS audit is a review of your tax return to check whether the income, deductions, and credits you reported are accurate and supported by records.

The IRS does not audit every return. They select returns based on patterns in the data, random sampling, or specific issues they have flagged. When they do audit you, they are looking for mistakes — either unintentional errors or deliberate underreporting. An audit does not automatically mean you owe money or face penalties. Many audits result in no change to what you owe, and some result in a refund.

The IRS conducts audits in three main ways: by mail (the most common), in person at an IRS office, or at your home or business. The method depends on what they are reviewing and how complex your return is. Most people never experience an audit in their lifetime. The audit rate has declined over the past decade and varies by income level and type of return.

Key Takeaways

  • The IRS selects returns for audit based on data patterns, random selection, or specific issues they have identified on your return.
  • Most audits happen by mail and focus on one or two specific items rather than your entire return.
  • You have the right to representation during an audit and can bring a tax professional, attorney, or enrolled agent with you.
  • The IRS will send you a formal notice by mail if you are selected; you should never respond to unsolicited calls or emails claiming to be the IRS.
  • If you disagree with the audit result, you have the right to appeal through the IRS Appeals Office before paying any additional tax.

How the IRS Selects Returns for Audit

The IRS uses a computer system called the Discriminant Index Function (DIF) to score returns and identify those most likely to contain errors. The system looks for unusual patterns — for example, deductions that are very high compared to your income, or income that does not match what employers or financial institutions reported to the IRS. The IRS also receives information from third parties: your employer reports your wages on a W-2, banks report interest on a 1099-INT, and brokers report investment sales on a 1099-B. If what you reported does not match what they reported, that triggers attention.

The IRS also conducts random audits as part of their National Research Program, which helps them understand where errors occur across different types of returns. Additionally, if you are involved in a business or have complex income sources, your return may be selected simply because those returns are audited at higher rates.

Being selected for an audit does not imply wrongdoing. It is a routine part of tax administration. However, if you have been dishonest on your return, an audit increases the risk that the IRS will discover it.

Types of Audits and What Each One Involves

Correspondence audits are conducted entirely by mail. The IRS sends you a letter asking you to provide documentation for specific items on your return — perhaps charitable donations, medical expenses, or business deductions. You gather the records, send them to the address on the letter, and the IRS reviews them. This is the most common type and usually takes a few weeks to a few months to resolve.

Office audits require you to meet with an IRS agent at a local IRS office. These are typically used when the IRS needs to examine more complex issues or multiple items on your return. You bring your records with you, and the agent asks questions about specific entries. Office audits usually take longer than correspondence audits and may require multiple meetings.

Field audits happen at your home, business, or your tax professional's office. The IRS agent comes to you, usually because they need to review books, records, or assets in person. Field audits are the most thorough and are typically reserved for business returns or returns with substantial income or deductions.

Your Rights During an Audit

You have the right to representation. You do not have to meet with the IRS alone. You can bring a certified public accountant (CPA), an enrolled agent, a tax attorney, or any other tax professional you trust. If you have a representative, the IRS can communicate with them instead of you, which can reduce stress and protect you from saying something that could complicate your case.

You also have the right to understand why the IRS is auditing you and what they are looking for. The audit notice will explain which items they want to review. You have the right to provide documentation and explanations for those items. If you do not have records, you can explain that to the agent; missing records do not automatically mean you lose a deduction, though it makes it harder to defend.

You have the right to appeal. If you disagree with the agent's findings, you can request an appeal to the IRS Appeals Office, which is separate from the audit division. This is a free process and happens before you have to pay any additional tax.

What to Do If You Receive an Audit Notice

First, verify that the notice is real. The IRS initiates audits by mail, never by phone, email, or text. If someone calls you claiming to be from the IRS and demanding immediate payment, hang up — that is a scam. Legitimate IRS notices come on official letterhead and include a specific notice number and the IRS office handling your case.

Read the notice carefully. It will tell you which tax year is being audited, which items the IRS wants to review, and what documents you need to provide. It will also give you a deadline — usually 30 days, though you can request more time.

Gather your records. Find receipts, invoices, bank statements, cancelled checks, or other documentation that supports the items the IRS is questioning. If you do not have original documents, copies, credit card statements, or other corroborating evidence can help. If you cannot find records, write down what you remember and explain why the records are not available.

Decide whether to represent yourself or hire help. If the audit is simple — perhaps just one deduction — you may feel comfortable responding on your own. If your return is complex or you are anxious about the process, hiring a tax professional is worth the cost. They know how the IRS works and can present your case in a way that is more likely to be accepted.

What Happens After You Respond

The IRS agent will review the documents you send or present. They may ask follow-up questions or request additional records. Once they have everything they need, they will make a information: no change (you owe nothing more), a partial change (you owe some additional tax), or a full change (the IRS disallows the deduction or item entirely).

If there is no change, the IRS sends you a letter saying so, and the audit is closed. If there is a change, the IRS sends you a notice explaining what they found and how much additional tax you owe, plus any interest and penalties. At this point, you have options: you can pay, you can request an appeal, or you can dispute the finding through the Tax Court if you disagree strongly.

Interest accrues on any additional tax owed from the original due date of the return. Penalties may also apply if the IRS finds that you understated your income or overstated deductions. The most common penalty is accuracy-related, which is 20% of the underpayment. Fraud penalties are much higher but require the IRS to prove intent to deceive.

How Long an Audit Takes

A correspondence audit typically takes two to six months from start to finish. An office or field audit can take several months to over a year, depending on how complex your return is and how quickly you provide records. The IRS has a statute of limitations: they generally cannot audit a return more than three years after you file it, or six years if they believe you underreported income by 25% or more. In rare cases involving fraud, there is no time limit.

You can request an extension if you need more time to gather records. The IRS is usually willing to grant reasonable extensions. If the process is taking a long time and you feel stuck, you can contact the Taxpayer Advocate Service, which is an independent office within the IRS that helps resolve disputes.

Frequently Asked Questions

Can I owe money even if I did nothing wrong?

Yes. An audit can result in additional tax owed if the IRS finds that you made an honest mistake — for example, you claimed a deduction you were not may have access to to, or you did not report income you received. The IRS distinguishes between mistakes and fraud. Mistakes result in back taxes and interest; fraud can result in much higher penalties.

What if I cannot find my receipts?

Missing receipts do not automatically disqualify a deduction. You can use other evidence: bank statements, credit card statements, cancelled checks, or written explanations of what you spent and why. The IRS understands that people do not always keep perfect records. However, the more documentation you can provide, the stronger your case.

Do I have to meet with the IRS in person?

For a correspondence audit, no — everything happens by mail. For an office or field audit, yes, unless you have a representative who can attend on your behalf. You can request that the audit be conducted by mail instead if you have a valid reason, though the IRS may decline if they need to examine records in person.

What happens if I disagree with the audit result?

You can request an appeal to the IRS Appeals Office within 30 days of receiving the audit result. The Appeals Office is separate from the audit division and will review your case fresh. If you still disagree after appeal, you can file a case in Tax Court, though this requires paying the tax first or meeting other conditions.

Will an audit affect future audits?

Not directly. Each return is scored independently. However, if an audit uncovers a pattern of errors or dishonesty, the IRS may scrutinize your future returns more closely. Conversely, if an audit finds no problems, that does not make you immune to future audits.