Receiving a notice from the IRS that you've been selected for an audit is unsettling, but it doesn't have to be. An audit is not an accusation of wrongdoing. In most cases, it's simply the IRS requesting documentation to verify information on your return. How you respond, what you bring, and whether you have professional representation can make a significant difference in the outcome.

This article walks you through why audits happen, what to expect at each stage, how to prepare, and when it makes sense to handle it yourself versus bringing in a tax professional.

Why Does the IRS Audit You (or Anyone)?

Most of the time, the IRS sends an audit notice based on random selection and computer screening. That algorithm mentioned above? Yeah, the IRS runs returns through that algorithm just like a manufacturer runs completed products through a quality assurance process. So many are kicked out just to check everything is going OK.

Also, if a return doesn't match the norms for other similar returns, the IRS might take a closer look and decide to audit you. Another chance for audit occurs if your return includes transactions with other taxpayers, such as business partners or investors, who were audited. Income differences and unusual deductions can cause your return to be flagged for an audit.

Other reasons for an IRS audit include:

• Home office deductions
• Conflicting third-party income reports like 1099s or W-2s
• Business use of a vehicle
• Rental losses
• Foreign currency transactions or bank accounts
• Hobby-related deductions (hobby losses)

None of these reasons show blatant disregard for the tax law, but they are common areas for fraud or exaggeration. 

The IRS has three years from the due date of the return to initiate an audit, and the agency starts most audits within a year of filing. Most are completed within a year.

Types of Audits

The IRS has three ways to audit.

A correspondent audit is also called a mail audit. You and the IRS go back and forth a couple of times via the US Postal Service, and everything is fixed. Correspondence audits generally include routine math errors or missing documentation.

An office examination audit is held at the local IRS branch office. It’s a little more stressful because you have to actually speak with an agent who is trying to determine if you reported all your income and only asked for legitimate deductions. You can feel put on the spot, but most of the time, everything is fine.

A field audit is the most extensive type of audit. The IRS chooses to expend resources to send an agent to your home, business, or accountant’s office to examine your records and files. The agency wants to confirm the information on your return is correct while you sweat it out.

Preparing for an Audit

First, understand the IRS contacts people by phone or mail, never by email. Generally, you receive a notification of an audit in the postal mail, including the specific information the IRS wants to examine. 

The letter contains a list of supplementary documents you might need to present. The agency gives you a couple of weeks to get everything together. You have 30 days to respond, but don't wait. Waiting allows the interest to grow on any unpaid balance you have.

Quickly gather and organize the forms requested by the IRS. Get copies, not the originals. If you misplaced anything, call immediately for a duplicate. Begin gathering early in case you need time to dig anything out.

What could the IRS ask for?

• Home mortgage statements
• Receipts 
• Previous tax returns
• Brokerage statements
• Retirement account records
• Pay stubs

The IRS wants to see any document supporting your tax return figures. That's why you save everything once you file. You never know if you're going to need it.

Should I Handle an IRS Audit Myself?

Whether you need professional representation depends largely on the type of audit you're facing and the complexity of your tax situation.

Correspondence audits are the most common type and the most manageable on your own. If the IRS is simply asking you to verify a specific deduction or clarify a discrepancy, and you have the documentation to support your return, responding yourself is often straightforward. The IRS letter will tell you exactly what they need — gather the documents, write a clear cover letter, and send everything via certified mail.

Office and field audits are a different matter. These involve sitting across from an IRS agent who is trained to ask questions in ways that can expand the scope of the audit if you're not careful. What you say, and what you volunteer without being asked, can open new lines of inquiry. At this level, having a licensed tax professional such as a CPA, IRS Enrolled Agent, or tax attorney represent you is strongly advisable. A representative can speak on your behalf, knows what the IRS can and cannot ask for, and can prevent the audit from expanding beyond its original scope.

You should strongly consider professional representation if any of the following apply:

• You are facing an office or field audit
• The audit involves a business return, rental income, or self-employment income
• The IRS is questioning multiple years of returns
• You have missing or incomplete records
• You are unsure whether your deductions were properly documented
• Prior audits have resulted in changes or penalties

The cost of professional audit representation is almost always less than the cost of an unfavorable audit outcome, particularly when penalties and interest are factored in. If you're unsure, most tax professionals will give you a clear assessment in an initial consultation.

Understand the Scope of the Audit

As you prepare, be sure you understand the reason for the audit. You don’t want to offer anything the IRS didn’t ask for. 

Mail audits are typically limited to a few items, while office and field audits are more extensive. In that case, prepare to answer in-depth questions about your finances and activities. 

You should call your tax professional to help you review your documents for anything more than a correspondence audit. Online filing services may offer audit defense services for a fee. Also, you can obtain a licensed tax professional to represent you, such as a CPA, tax attorney, or IRS Enrolled Agent.

During the Audit

How you conduct yourself during an audit matters as much as the documents you bring. Whether you're handling it yourself or attending alongside a representative, understanding the ground rules of an audit will help you stay in control of the process.

Only answer what is asked. This is the single most important rule during any audit. IRS agents are trained interviewers and may ask open-ended questions. Answer specifically and concisely — do not offer additional context, explain your reasoning at length, or reference other years or other deductions unprompted. Every piece of information you volunteer is a potential starting point for additional scrutiny.

Bring copies, never originals. Submit copies of all requested documents and keep your originals. Once you hand something to an agent, you lose control of it. Bring everything organized and clearly labeled so you appear prepared and cooperative.

What to bring to your appointment:

• A copy of the audit notification letter
• Copies of all documents requested in the letter
• A copy of the tax return under audit
• Copies of returns for the two prior years
• Copies of documentation provided to your tax preparer
• Copies of results from any prior audits
• Any other IRS correspondence related to the tax year in question

You have the right to representation. If at any point during the audit you feel uncomfortable, unprepared, or that the questioning is exceeding the original scope, you can pause and request time to consult with a tax professional. You are never required to continue an interview without representation present. Invoking this right is not an admission of anything — it is a standard and protected part of the audit process.

Stay professional and cooperative. Being defensive, argumentative, or evasive with an agent will not help your case. Auditors have a job to do, and a cooperative, well-documented response is the fastest path to a clean resolution.

Potential Outcomes

Every IRS audit ends in one of three ways:

No changes. The IRS reviews your documentation and accepts your return as filed. No additional tax is owed. This is a common outcome, particularly for correspondence audits where you have solid records. You receive a closing letter and the matter is resolved.

Agreed changes. The IRS proposes changes to your return (typically additional tax owed, plus interest) and you agree with the findings. You sign the examination report and arrange payment. If you can't pay the full amount immediately, you can request an installment agreement at this stage rather than paying in one lump sum.

Disputed changes. You disagree with the IRS's proposed changes. This is where many people assume the process ends, but it doesn't. You have several options to challenge the outcome.

• Request a supervisor review. Before formally appealing, you can ask to speak with the examining agent's manager. This informal step sometimes resolves disagreements without escalating further.
• File an appeal with the IRS Office of Appeals. If the supervisor review doesn't resolve the issue, you can file a formal appeal. The IRS Office of Appeals is an independent body within the IRS — separate from the examination division — and it reviews disputed cases without bias toward either side. Most disputes are resolved at this stage.
• Petition the U.S. Tax Court. If the Appeals process doesn't produce an acceptable result, you can take your case to the U.S. Tax Court, which handles tax disputes without requiring you to pay the disputed amount first. This is a formal legal proceeding and having a tax attorney represent you is highly advisable at this stage.
• Request help from the Taxpayer Advocate Service. If you're experiencing significant hardship as a result of the audit (or if the IRS has been unresponsive or has made errors in handling your case) the Taxpayer Advocate Service (TAS) is an independent organization within the IRS that advocates on your behalf at no cost.

One important note on timing: interest on any unpaid tax balance accrues daily from the original return due date, regardless of where you are in the appeals process. Resolving the dispute as quickly as possible, even if you're appealing, is in your financial interest.

Protect Yourself in Case of Audit

However small, there is always a chance that you will be tagged for an audit. Protect yourself by keeping tax returns and records for at least three years. Save your checkbook registers and organize receipts for major purchases by date. File your bills in folders and create a journal to keep evidence of deductible information. 

Keep all your tax documents in one location for easy access. If you receive a notification from the IRS, you are ready for an audit. Engage your tax professional or Top Tax Defenders to help you.

Frequently Asked Questions About Fighting an IRS Audit

What does it mean to "fight" an IRS audit?

Fighting an audit doesn't necessarily mean going to court. In most cases it means responding to the IRS with thorough documentation to support your return, disputing proposed changes you believe are incorrect, and if needed, appealing the outcome through the IRS Office of Appeals. Most audits are resolved long before they reach Tax Court.

How long does an IRS audit take?

Most audits are initiated within a year of filing and completed within another year. Correspondence audits can be resolved in a matter of weeks if you respond promptly with the right documentation. Office and field audits typically take longer, especially if additional documentation is requested or an appeal is filed.

What happens if I ignore an IRS audit notice?

Ignoring an audit notice is one of the worst things you can do. If you don't respond, the IRS will make a determination based on the information it already has, which almost always means a higher tax bill, plus penalties and interest. The IRS can also escalate collection activity, including tax liens and levies, against unresolved audit assessments.

Can the IRS audit me for more than one year at a time?

Yes. While the IRS typically audits one tax year at a time, if a significant issue is found it may expand the audit to cover the two prior years as well. This is one reason why only answering what is asked, and not volunteering information about other years, matters so much during an audit.

What is the IRS statute of limitations on audits?

Generally, the IRS has three years from the date your return was filed, or the due date of the return, whichever is later, to initiate an audit. That window extends to six years if the IRS believes you underreported income by more than 25 percent. There is no statute of limitations if the IRS determines a fraudulent return was filed.

Can I appeal an IRS audit decision?

Yes. If you disagree with the outcome of an audit, you have the right to appeal. Your first step is requesting a supervisor review with the examining agent's manager. From there you can file a formal appeal with the IRS Office of Appeals, and if necessary, petition the U.S. Tax Court. Most disputes are resolved at the Appeals level without going to court.

What is the difference between an IRS audit and a criminal tax investigation?

A standard audit is a civil review of your tax return to verify accuracy. It is not a criminal proceeding. A criminal tax investigation is a separate process conducted by IRS Criminal Investigation (IRS-CI) and is reserved for cases involving suspected fraud or tax evasion. If your civil audit is ever referred to IRS-CI, you should retain a tax attorney immediately.

Do I need a tax professional to handle an IRS audit?

It depends on the type of audit. Correspondence audits over straightforward issues can often be handled without professional help if you have good records. Office audits, field audits, audits involving business income, or any audit where multiple years or large sums are in question should be handled with professional representation. The risk of saying the wrong thing, producing too much documentation, or missing an appeal deadline is too high to navigate alone.