The first thing to figure out when an audit notice arrives is which type of audit you’re facing. The IRS uses three basic formats — correspondence, office, and field — and each one calls for a different defense. Knowing which type you have tells you what to expect, who you’ll deal with, and how much is realistically on the table.
1. Correspondence Audits
By volume, correspondence audits are by far the most common — around 75% of all IRS individual examinations. The entire audit happens by mail. You receive a letter, mail in your documents, and weeks or months later you get a response. There is no examiner you meet, no office to visit, and usually no one to call who has actually read your file.
Typical issues: Earned Income Credit eligibility, dependents, education credits, charitable contributions, unreimbursed business expenses, and itemized deductions that look statistically unusual.
What to expect: A Letter 566 or CP75 series notice listing the items in question and what to send in. You have 30 days to respond. After you respond, the IRS may accept your documentation and close the audit, request more information, or propose adjustments.
How to win: Send clean, organized, complete documentation the first time. If receipts are missing, reconstruct them with bank or credit card statements, and explain in a cover memo. Be concise — the person reviewing your response usually has a stack of files and won’t read 60 pages of explanation.
2. Office Audits
An office audit is conducted at a local IRS office, typically by a tax compliance officer. You’ll receive a Letter 2202 or similar notice scheduling an appointment, usually two to four hours, with a list of records to bring. Office audits target a small number of specific issues rather than the entire return.
Typical issues: Schedule C business income and expenses, rental real estate (Schedule E), large itemized deductions, gains and losses on sales of property, and items the IRS thinks were misreported.
What to expect: An in-person interview where the tax compliance officer asks questions about the return and reviews your records. The officer will often issue follow-up IDRs after the meeting if records are incomplete.
How to win: Either bring representation or, at minimum, prepare with someone before the meeting. Answer the questions asked and nothing more. Do not bring records that weren’t requested. Take notes during the meeting and confirm by email afterward what was agreed and what is still open.
3. Field Audits
Field audits are conducted by revenue agents — the IRS’s most senior examiners — and they happen at your home, your business, or your representative’s office. Field audits are reserved for complex returns: small and mid-size businesses, high-net-worth individuals, returns with international elements, and any return where the IRS suspects the issue cannot be resolved by mail.
Typical issues: Entire business returns (1120, 1120-S, 1065), Schedule C businesses over a certain size, multiple-entity structures, large charitable deductions including conservation easements, and returns with potential fraud indicators.
What to expect: A scheduled opening conference, multiple IDRs over several months, possible third-party contacts and summonses, indirect-method analysis (bank deposits, net worth, source-and-application of funds), and a comprehensive examination of the entire return.
How to win: Hire a tax attorney or CPA before the opening conference, ideally before the IRS sees any documents. Insist that the audit be conducted at the representative’s office, not your home or business, to limit informal questioning. Build a clear record on every issue. And do not let the agent expand the audit to additional years or related entities without a specific written request.
How to Tell Which Type You Have
Look at the notice. Correspondence audits ask you to mail documents in by a deadline — there is no meeting. Office audits ask you to schedule an appointment at a local IRS office. Field audits introduce a specific revenue agent who will contact you to schedule an opening conference at a location convenient to them.
The type of audit also signals how much the IRS is willing to invest in your case. Correspondence audits are designed for volume; field audits are reserved for cases worth a significant amount of tax. Knowing which type you have helps you calibrate your own response.
A Strategy for Each Type
The defense for a correspondence audit is not the same as the defense for a field audit. Win Your IRS Audit walks through each type — plus BBA partnership audits, ERC examinations, and more — with the specific tactics that work.