How to Prepare for a Tax Audit: IRS Exam Steps for 2026

Knowing how to prepare for a tax audit starts with the IRS letter itself: confirm it is genuine, note every response date, work out whether the exam is by mail, at an IRS office or at your business, and then build a records file that answers only the items the examiner listed. Decide early who will speak for you, and file the authorization before the first appointment.

The steps below follow the order an IRS examination usually runs in, from the first letter through the Information Document Request (IDR), the interview, the examiner's report and the appeal options. They are written for small business owners and the accountants who support them, using the procedures in IRS Publication 556, Publication 1 and the Internal Revenue Manual.

Step 1: Confirm the Letter Is a Real Audit Notice

The IRS starts examinations on paper. Its audit page says, "Should your account be selected for audit, we will notify you by mail. We won't initiate an audit by telephone" (IRS, IRS audits). A phone call or email claiming to open an audit should be treated as a likely scam until you match it to a letter.

Note the tax year, the form under review and the response or appointment date, and put that date in a shared calendar the same day. Then confirm whether the letter is an examination at all. A CP2000 is an automated underreporting notice that compares your return with third-party information returns, and it follows a different response path, explained in our guide to the IRS CP2000 notice and proposed changes.

Step 2: Identify Which Type of IRS Audit You Face

The IRS describes its methods simply: it "conducts audits either by mail or through an in-person interview to review your records. The interview may be at an IRS office (office audit) or at the taxpayer's home, place of business, or accountant's/representative's office (field audit)." Each format changes how you prepare.

Correspondence exams usually cover a few line items, while office and field exams look wider. If the place or timing does not work, Publication 556 says "the examiner will try to work out something more suitable," though the IRS makes the final decision. You can also ask for the case to be moved to the area "where your books and records are located" if that makes the exam faster (IRS Publication 556).

Step 3: Decide Who Will Represent You and File Form 2848

You can handle an exam yourself. Many business owners choose a representative who already knows the procedure. Publication 1 lists "The Right to Retain Representation" among the ten taxpayer rights (IRS Publication 1). Publication 556 adds that "If you want someone to represent you in your absence, you must furnish that person with proper written authorization. You can use Form 2848 or any other properly written authorization."

Eligible representatives include attorneys, CPAs and enrolled agents, the IRS-licensed tax specialists. Our guide to Form 2848 and Form 8821 authorizations explains why an audit needs a full power of attorney.

The timing rules work in your favor once representation is in place:

• The Internal Revenue Manual tells examiners to "allow the taxpayer a minimum of 10 business days to secure a representative" when a taxpayer says they will get one (IRM 4.10.2).
• "When a valid Form 2848 or Form 8821 has been received from the taxpayer, the initial appointment must be scheduled with the representative."
• If you want to stop an interview to consult a representative, Publication 556 says "In most cases, the IRS must suspend the interview and reschedule it."

Form 2848 can be uploaded through the IRS online submission tool. The IRS asks you to "Submit one form at a time, even for married filing jointly taxpayers," and warns, "If you already faxed or mailed a form, don't submit it online" (IRS, Submit Forms 2848 and 8821 online). Duplicate submissions slow processing, so pick one channel.

Step 4: Read the Information Document Request Line by Line

Form 4564, the Information Document Request, sets the scope of what you hand over. Under IRM 4.10.2.10.1, "The Form 4564 must always include a date for submission of the requested information or documents." Examiners are also advised to note that they "will probably request additional records as the examination progresses," so treat the first IDR as a starting list.

Work through the IDR in this order:

1. Number each item and copy its exact wording into a tracking sheet with the due date.
2. Map each item to the ledger accounts, statements or contracts that answer it.
3. Ask the examiner in writing to clarify any broad item, or to extend an unrealistic deadline, well before the due date.

Answer what the IDR asks for. Handing over every ledger and statement for three years invites questions about items that were never in scope, while refusing access "will only prolong the examination," as the IRM puts it.

Step 5: Build the Records File the Examiner Will Test

The IRS does not require a particular bookkeeping system. It says, "You may choose any recordkeeping system suited to your business that clearly shows your income and expenses," and "Supporting documents include sales slips, paid bills, invoices, receipts, deposit slips, and canceled checks" (IRS, What kind of records should I keep). The IRS audit page also notes that it "accepts some electronic records in lieu of or in addition to other types of records," so confirm the format with your examiner before you scan or export everything.

For most small business exams, the core file includes:

• the filed return and the trial balance or general ledger that ties to it;
• bank and credit card statements for the full year, with month-end reconciliations;
• invoices and deposit records that support gross receipts;
• receipts, bills and contracts for each expense line the IDR names;
• payroll reports and Forms W-2 and 1099 issued;
• asset invoices, the depreciation schedule, and mileage logs where vehicle costs are in scope.

Vehicle, travel and gift expenses carry their own substantiation rules, which our Publication 463 guide to travel, meal, gift and car expenses covers in detail. A business that already runs a disciplined month-end process will find this step much faster, and our monthly close checklist with AP, AR and reconciliation SOPs is a useful model for keeping reconciliations audit-ready all year.

How long to keep these records depends on the situation. The IRS baseline is "Keep records for 3 years," with longer periods for underreported income, bad debts and worthless securities, and "Keep employment tax records for at least 4 years after the date that the tax becomes due or is paid, whichever is later" (IRS, How long should I keep records). Record retention is a separate question from how many tax years an exam can reach, which our guide on how far back the IRS can audit you explains.

Step 6: Package Your Response So It Is Easy to Review

Send a cover letter that lists each IDR item, a short answer, and the exhibit numbers that support it. Index the exhibits so each page is easy to find, and keep an identical copy of everything you sent. Our IRS audit response pack with a sample cover letter and indexing method shows the format in detail.

Before you send anything, review the return for the issues examiners commonly raise. Our article on common audit issues for small businesses and how to fix them lists the usual problems, and our list of common IRS audit triggers explains which return patterns tend to draw attention in the first place. If you find an error the examiner has not raised, discuss it with your representative before deciding how to disclose it.

Step 7: Prepare for the Interview

For office and field audits, the interview is where most adjustments are proposed or dropped. A few rules from Publication 556 shape the preparation:

• Recording. "You can make an audio recording of the examination interview. Your request to record the interview should be made in writing. You must notify the examiner 10 days in advance and bring your own recording equipment."
• Explanations. "Any proposed changes to your return will be explained to you or your authorized representative."
• Repeat exams. If the same items were examined "in either of the 2 previous years and no change was proposed," contact the IRS quickly to ask whether the exam should be discontinued.

Rehearse how revenue is recorded and how expenses are approved. Keep answers factual, and offer a written follow-up when you do not know an answer. The representative can attend alone once Form 2848 is on file.

Step 8: Know Your Options When the Examiner Proposes Changes

An exam ends in one of three ways. The IRS audit page defines them as "No change," "Agreed," where you "understand and agree with the changes," and "Disagreed," where you "understand but disagree with the changes."

If you agree, Publication 556 says "you can sign an agreement form and pay any additional tax you may owe. You must pay interest on any additional tax." If the balance is too large to pay at once, our guide to Form 9465 installment agreements covers payment plans. Penalties added in the exam may qualify for relief, and our guide to Form 843 penalty abatement explains the request.

If you disagree, the IRS page notes you can request a conference with an IRS manager, use mediation, or file an appeal while enough time remains on the statute of limitations. The formal path runs through two letters:

• 30-day letter. Publication 556 says "You generally have 30 days from the date of the 30-day letter to tell the IRS whether you will accept or appeal the proposed changes." It comes with the examination report, an agreement or waiver form and Publication 5.
• Protest or small case request. "If the total amount for any tax period is not more than $25,000, you may make a small case request instead of filing a formal written protest." The total includes the proposed tax change and penalties.
• 90-day letter. If you do not respond or do not settle in Appeals, the IRS issues a notice of deficiency. "You will have 90 days (150 days if it is addressed to you outside the United States) from the date of this notice to file a petition with the Tax Court."
• Small tax case. If the amount is "$50,000 or less for any 1 tax year or period," you can ask the Tax Court to use its small tax case procedure, whose decisions cannot be appealed.

Publication 1 adds that court costs are recoverable only if "you tried to resolve your case administratively, including going through the appeals system."

Worked Example: How Records Change the Exam Result

This example is illustrative. A sole proprietor's 2024 return reported $61,000 of tax. A field exam targets $38,000 of vehicle and travel deductions, and the examiner's first report proposes $9,800 of additional tax because the mileage log was incomplete.

The accuracy-related penalty "is 20% of the portion of the underpayment of tax" tied to negligence or a substantial understatement (IRS, Accuracy-related penalty). For individuals, an understatement is substantial when it exceeds the greater of 10% of the tax required to be shown or $5,000. Here the tax required to be shown is the corrected tax: $61,000 plus the additional tax.

In Scenario B, the owner rebuilds the mileage log from calendar entries, fuel receipts and client invoices, and the examiner accepts part of the deduction. Additional tax drops by $5,200 and the substantial understatement penalty falls away, for a total of $7,160 less before interest. A negligence penalty could still apply to the remaining adjustment, which is where a reasonable-cause argument comes in.

How to Prepare for a Tax Audit Before Any Letter Arrives

Reconcile bank and card accounts every month, keep receipts attached to transactions in your accounting software, separate personal spending from business accounts, and keep a short memo on any large or unusual item at the time you book it. Each of these habits makes a future IDR a retrieval exercise instead of a reconstruction project. Keep a standing folder for each tax year with the filed return, the year-end trial balance, the fixed asset register and payroll filings.

Frequently Asked Questions

How long do I have to respond to an IRS audit letter? The deadline is printed in the letter or on Form 4564, and the IRM requires every IDR to include a submission date. If you need more time, ask in writing before the date passes and confirm the new date.

Will the IRS ever call to start an audit? The IRS says it will notify you by mail and that it won't initiate an audit by telephone. Treat any unexpected call or email about a new audit with caution until you can match it to a letter.

Can my accountant attend the audit without me? Yes, if you give written authorization. Publication 556 says you can use Form 2848 or any other properly written authorization, and once a valid Form 2848 is received the initial appointment must be scheduled with the representative.

What happens if I do not agree with the audit results? You can ask for a conference with the examiner's manager, use mediation, or appeal within 30 days of the 30-day letter. If no agreement is reached, the IRS issues a 90-day letter, and you have 90 days to petition the Tax Court.

What records should I gather to prepare for a tax audit? Start with the items listed on the IDR, then add the general ledger, reconciled bank and card statements, and receipts for each expense line under review.

Next Step

Madras Accountancy supports US businesses and CPA firms with bookkeeping, reconciliations, tax preparation and audit support, including organizing records and indexed workpapers for IRS document requests. To talk through your records before an exam or during one, contact our team.