Types of IRS Audits Explained

Understanding Correspondence Audits, Office Audits, and Field Audits

When taxpayers receive a letter from the Internal Revenue Service informing them that their return has been selected for examination, one of the first questions they usually ask is, " How serious is this?" The answer depends largely on what type of IRS audit has been initiated.

Many people simply say they are "being audited," but that phrase can describe several very different examination procedures. Some audits are completed entirely through the mail with only a few supporting documents. Others involve in-person meetings at an IRS office. The most comprehensive examinations may take place at your business and require months of document production, interviews, and detailed financial analysis.

Understanding which type of audit you are facing is one of the most important steps in determining how to respond. The procedures, expectations, level of scrutiny, and potential risks differ significantly from one type of examination to another.

Why the Type of IRS Audit Matters

Although every IRS examination has the same basic objective—determining whether a tax return accurately reflects the taxpayer's tax liability—not every examination follows the same procedures. The IRS uses different examination programs depending on the complexity of the issues, the amount of tax involved, the records needed, and the type of taxpayer being examined.

Knowing the type of audit you have helps answer important practical questions before you begin responding:

• Will I need to meet with the IRS in person?
• Will the IRS visit my business?
• How much documentation should I expect to produce?
• Is the audit focused on one issue or my entire return?
• Can the examination expand into other tax years?
• Should I have professional representation before speaking with the examiner?

The answers vary considerably depending on whether your examination is classified as a Correspondence Audit, an Office Audit, or a Field Audit.

Comparison of the Three Primary IRS Audit Types

Correspondence Audits

A correspondence audit is the most common type of IRS examination. As the name suggests, these audits are conducted primarily through written correspondence rather than in-person meetings. The IRS requests specific documentation supporting one or more items reported on a tax return, and the taxpayer responds by mailing or electronically uploading the requested records.

Although correspondence audits are generally considered the least complex of the three audit types, they should not be dismissed as routine paperwork. Failure to provide adequate documentation—or misunderstanding what the IRS is actually requesting—can still result in additional tax, penalties, and interest.

Correspondence audits commonly focus on a limited number of issues rather than the entire tax return. Examples include charitable contributions, education credits, brokerage basis reporting, retirement distributions, dependency claims, business expenses, cryptocurrency transactions, and income matching issues reported by third parties.

Office Audits

An Office Audit is the next level of IRS examination. Unlike a correspondence audit, which is generally handled through the mail or electronically, an office audit requires the taxpayer—or their authorized representative—to appear at an IRS office for one or more meetings with the examiner.

Office audits typically involve more complex tax issues than correspondence examinations. Rather than requesting documentation for one isolated item, the IRS often reviews multiple deductions, sources of income, or areas of the return simultaneously. While these examinations are generally narrower than field audits, they require considerably more preparation than many taxpayers expect.

Most office audits are conducted by an IRS Tax Compliance Officer, although Revenue Agents may conduct office examinations in certain circumstances. The examiner will typically review documents before or during the meeting, ask questions about the taxpayer's financial activities, and determine whether additional documentation will be required before completing the examination.

What Happens During an Office Audit?

The examination usually begins with an appointment letter identifying the tax year under review and requesting specific documentation. Depending upon the issues involved, the IRS may ask for bank statements, canceled checks, invoices, mileage logs, brokerage statements, QuickBooks reports, depreciation schedules, payroll information, or other records supporting items reported on the return.

At the appointment, the examiner will generally review the documents provided, ask questions regarding how transactions occurred, and compare the records against the tax return. If questions remain unanswered, additional Information Document Requests (IDRs) may be issued after the meeting.

Many taxpayers mistakenly assume the appointment is simply an opportunity to hand the IRS a stack of receipts. In reality, the meeting often serves two purposes. First, the examiner evaluates the documentation. Second, the examiner evaluates the taxpayer's explanations regarding the transactions reflected in those documents.

Issues Commonly Reviewed During Office Audits

Office audits frequently involve taxpayers with self-employment income, rental real estate, investment activity, or closely held businesses. Some of the most common issues include:

Preparing for an Office Audit

Preparation begins long before walking into the IRS office. Documents should be reviewed for completeness, reconciled to the tax return, and organized in a logical manner that allows the examiner to quickly understand the taxpayer's position. Poorly organized records frequently result in additional questions—not necessarily because the deduction is improper, but because the supporting information is difficult to follow.

Equally important is understanding the scope of the examination. Taxpayers should know exactly what issues the IRS is reviewing before attempting to explain transactions or provide additional information. Responding beyond the scope of the audit can unintentionally introduce new issues that were never part of the examination.

Field Audits

A Field Audit is the most comprehensive type of IRS civil examination. Unlike correspondence audits or office audits, a field audit generally takes place at the taxpayer's place of business, the office of the taxpayer's CPA or attorney, or another mutually agreed-upon location. These examinations are typically conducted by an IRS Revenue Agent and often involve businesses, self-employed individuals, partnerships, S corporations, trusts, and high-income taxpayers with more complex financial activities.

Although every examination is unique, field audits generally involve substantially more documentation, more interaction with the IRS, and a significantly greater opportunity for the examination to expand beyond the issue that originally triggered the audit. They frequently span several months and, in larger cases, may continue for a year or more.

Because field audits often involve accounting systems, financial statements, internal controls, payroll records, inventory, and business operations, they require a much different strategy than simply responding to a letter requesting receipts.

What Does a Revenue Agent Actually Do?

Many taxpayers mistakenly believe a Revenue Agent simply reviews receipts and compares them to the tax return. In reality, the examination is much broader. The agent is attempting to determine whether the taxpayer's books and records accurately reflect taxable income and whether the accounting records support the positions taken on the return.

Depending upon the issues involved, the Revenue Agent may review financial statements, trial balances, QuickBooks files, bank statements, payroll reports, depreciation schedules, loan agreements, shareholder distributions, inventory records, purchase invoices, vendor files, customer contracts, and other business records.

The examination is rarely limited to verifying individual receipts. Instead, the IRS often evaluates whether the financial records tell a consistent story. The examiner may compare tax returns to accounting records, reconcile deposits to reported income, evaluate unusual fluctuations between years, analyze gross profit percentages, or investigate transactions that appear inconsistent with the taxpayer's overall financial picture.

Information Document Requests (IDRs)

Most field audits involve one or more Information Document Requests, commonly referred to as IDRs. These formal requests identify the records the IRS wants to examine and frequently become the roadmap for the remainder of the audit.

An IDR may request accounting records, bank statements, reconciliations, payroll reports, contracts, invoices, QuickBooks backups, depreciation schedules, organizational documents, or virtually any other information the examiner believes is relevant to the examination.

Receiving multiple IDRs during a field audit is entirely normal. As the examiner reviews information, additional questions frequently arise, leading to follow-up requests for clarification or supporting documentation.

Interviews During a Field Audit

Interviews are considerably more common during field audits than during other examination types. The Revenue Agent may interview business owners, corporate officers, partners, accounting personnel, bookkeepers, or other individuals involved in the business's financial operations.

Questions often focus on how the business earns revenue, how expenses are approved, who maintains the accounting records, how cash is handled, who has authority to sign checks, how payroll is processed, and whether bookkeeping procedures changed during the years under examination.

These interviews are not intended to intimidate taxpayers. Rather, they help the examiner understand the business's operations and evaluate whether the accounting records accurately reflect those operations.

How Each Type of IRS Audit Typically Progresses

How Field Audits Can Expand

One characteristic that distinguishes field audits from correspondence examinations is the possibility that the examination's scope may expand as new information is developed. Expansion does not occur in every audit, but it is considerably more common during field examinations.

For example, an examination that initially focuses on business expenses may later involve payroll issues, shareholder distributions, depreciation, inventory accounting, related entities, or additional tax years if the examiner discovers information suggesting those issues warrant further review.

This does not mean every field audit becomes a broad investigation. It simply illustrates why understanding the scope of the examination—and responding carefully throughout the process—is so important.

Common Misconceptions About IRS Audits

Which Type of IRS Audit Is the Most Serious?

Although every examination should be taken seriously, field audits generally involve the greatest amount of documentation, the most extensive interaction with the IRS, and the highest likelihood that additional issues may be identified during the examination. That is why business owners, partnerships, S corporations, and high-income taxpayers frequently seek professional representation early in the process.

What Happens After the IRS Completes Its Examination?

Regardless of the type of audit, every IRS examination eventually reaches the point where the examiner evaluates the available evidence and determines whether adjustments to the tax return are appropriate. Contrary to what many taxpayers believe, this stage is rarely a simple "pass or fail" decision. Instead, the examination often becomes a discussion about documentation, interpretation of the tax law, accounting treatment, and the strength of the available evidence.

In many examinations, the IRS initially proposes adjustments that are later modified—or eliminated entirely—after additional documentation or explanations are provided. Other audits conclude with no changes at all. The outcome depends upon the facts, the quality of the records, and whether the taxpayer can adequately support the positions taken on the return.

Possible Outcomes of an IRS Audit

If You Disagree With the Examiner

Receiving proposed adjustments does not necessarily mean the examination is over. Taxpayers frequently have opportunities to discuss factual issues with the examiner, submit additional documentation, clarify misunderstandings, or provide legal authority supporting the positions reported on the return.

If disagreements remain after those discussions, many cases may proceed to the IRS Independent Office of Appeals. Appeals serves a different function than Examination. Rather than developing new facts, Appeals evaluates the strengths and weaknesses of both positions and attempts to resolve disputes without litigation whenever possible.

Because the appeals process involves different procedures and considerations than the audit itself, we discuss it in greater detail on our dedicated IRS Audit Appeals page.

When Does Professional Representation Make Sense?

Not every IRS audit requires professional representation. However, as the complexity of the examination increases, so does the value of having an experienced CPA manage communications, organize documentation, and help present your position effectively.

Frequently Asked Questions

Which type of IRS audit is the most serious?

Generally, field audits involve the broadest scope and the highest level of IRS scrutiny. However, any examination should be taken seriously because even a correspondence audit can result in additional tax if documentation is not provided.

Can an office audit become a field audit?

Yes. If the IRS determines additional issues require review or believes a business examination should occur on-site, the examination may be expanded.

Can the IRS audit more than one year?

Yes. If similar issues exist in other years, the examination may expand beyond the original tax year identified in the audit notice.

Do I have to meet with the IRS myself?

Not always. In many situations, a properly authorized CPA, attorney, or enrolled agent can communicate directly with the IRS and handle much of the examination on your behalf.

Can missing records automatically cause me to lose the audit?

No. While complete documentation is always preferable, alternative evidence, reconstructed records, or third-party documentation may sometimes support the taxpayer's position depending on the circumstances.

Final Thoughts

Understanding the different types of IRS audits is one of the best ways to reduce uncertainty after receiving an audit notice. Correspondence audits, office audits, and field audits each follow different procedures, involve different levels of documentation, and require different strategies.

Regardless of the type of examination, the objective remains the same: present accurate information, support the positions reported on the return, and resolve the examination fairly under the Internal Revenue Code. Approaching the process in an organized and informed manner often leads to a more efficient examination and a better overall outcome.

Not Sure What Type of IRS Audit You're Facing?

The first step in responding effectively is understanding the type of examination the IRS has initiated. If you've received an IRS audit notice and would like to discuss your situation, Boulanger CPA and Consulting PC provides CPA-led representation for taxpayers facing correspondence, office, and field audits.