Tax Talk Thursday: The Audit Readiness Checklist - What to Have in Place Before the IRS Letter Arrives

Most taxpayers think about audits only after an envelope from the IRS shows up. By then, the outcome is already largely decided — not by what you say to the examiner, but by what records you kept two or three years ago.

An audit is not an accusation. It is a request to prove what you reported. Taxpayers who lose audits usually did not cheat; they simply cannot substantiate a deduction they were entitled to, or they cannot explain a bank deposit that was never income in the first place.

This post walks through a practical audit readiness checklist — what to keep, how long to keep it, where the IRS tends to look, and what to do in the first 72 hours if a notice arrives. October is the right time to do this: there is still a full quarter left to clean up 2026 records before they lock in.

What an IRS Audit Actually Looks Like

The word "audit" covers three very different experiences:

•       Correspondence examination — conducted entirely by mail, usually focused on one or two specific items (a credit, a deduction, unreported income). This is by far the most common type.

•       Office examination — you or your representative meet with an IRS tax compliance officer, typically covering several issues.

•       Field examination — a revenue agent reviews your books in depth, often at your business or your representative's office. These are most common for businesses and higher-income individuals with complex returns.

Separately, a CP2000 notice is technically not an audit at all. It is an automated mismatch notice generated when the income on your return does not match what third parties (employers, banks, brokers, payment platforms) reported to the IRS. It still requires a timely, documented response.

A warning about scams: the IRS initiates contact by mail. It does not open an audit by email, text message, or social media, and it does not demand payment by gift card or wire. If a "notice" arrives any other way, verify it before responding.

How Long You Are Exposed: The Statute of Limitations

Your recordkeeping window is driven by how long the IRS can assess additional tax. Keep records at least until the assessment period for that return expires.

Situation	IRS Assessment Window	Authority
General rule (return filed on time)	3 years from the later of the due date or filing date	IRC §6501(a)
Omitted more than 25% of gross income	6 years	IRC §6501(e)
Omitted more than $5,000 of income from specified foreign financial assets	6 years	IRC §6501(e)(1)(A)(ii)
Required foreign information return not filed (e.g., Forms 5471, 8938, 3520, 8865)	Remains open until 3 years after the information is furnished	IRC §6501(c)(8)
Fraudulent return, or no return filed	No limit	IRC §6501(c)

The foreign information return rule is the one that surprises people most. If a required Form 5471 or 8938 was never filed, the statute for that tax year can remain open. Where the failure was due to reasonable cause, the extended period applies only to items related to the missing information return; otherwise, it can apply to the entire return.

Other retention rules worth knowing (see IRS Publication 583):

•       Employment tax records: at least 4 years after the tax becomes due or is paid, whichever is later.

•       Property and investment records: until the statute expires for the year you sell the asset — which can mean decades for a home, rental property, or long-held stock.

•       Bad debts and worthless securities: 7 years.

•       Entity basis and carryforwards: keep the full history for as long as the basis or carryforward affects a return that is still open.

The Audit Readiness Checklist

1. Income Can Be Reconciled to the Bank

Examiners frequently start with a bank deposits analysis: total deposits across all accounts, minus non-taxable items, compared to reported income. Every deposit you cannot explain is presumed to be income.

☐     Every Form W-2, 1099-NEC, 1099-MISC, 1099-K, 1099-B, 1099-INT, 1099-DIV, and K-1 matches what is on the return.

☐     Gross receipts reconcile to 1099-K totals — with documentation for refunds, chargebacks, fees, and personal reimbursements that inflate the 1099-K figure.

☐     Transfers between your own accounts are documented so they are not double-counted as income.

☐     Loan proceeds, gifts, inheritances, and sales of personal items are documented with their source (loan agreement, gift letter, estate paperwork).

2. Every Deduction Has Proof of Amount AND Business Purpose

A receipt proves you spent money. It does not prove the expense was deductible. For most business deductions, you need both.

☐     Receipts or invoices for each expense, tied to a payment record (card or bank statement).

☐     A note of business purpose for meals, travel, and gifts — who, what, when, where, and why.

☐     Business and personal spending run through separate accounts and cards.

Section 274(d) items are held to a higher standard. Travel, gifts, and listed property (including vehicles) require adequate records or sufficient corroborating evidence. The courts' "Cohan rule," which sometimes allows a reasonable estimate when records are incomplete, does not apply to these categories. No log, no deduction.

3. Vehicle and Home Office Claims Are Documented Contemporaneously

☐     A mileage log kept during the year — date, destination, business purpose, miles — plus start-of-year and end-of-year odometer readings.

☐     For actual-expense vehicles: purchase documents, depreciation history, and total vs. business miles.

☐     For a home office: a floor plan or measurements, photos showing regular and exclusive use, and the utility, insurance, and mortgage interest or rent records used in the calculation.

A mileage log reconstructed from memory during an audit carries far less weight than one kept at the time. Mileage tracking apps that log trips automatically are an easy fix.

4. S Corporation and Partnership Items Are Supported

☐     Reasonable compensation: documentation of how the owner-employee's salary was set (duties, hours, comparable market wages).

☐     Accountable plan: a written plan for reimbursing owners' business expenses, with expense reports and substantiation for each reimbursement.

☐     Shareholder and partner basis: a running basis schedule, especially if losses or distributions were claimed.

☐     Shareholder loans: signed notes, interest terms, and a repayment history — not just a journal entry labeled "loan."

☐     Minutes or written consents for significant decisions (distributions, loans, large purchases).

5. Foreign Accounts and Assets Are Fully Reported

☐     FBAR (FinCEN Form 114) filed for each year aggregate foreign account balances exceeded $10,000 at any point.

☐     Form 8938 filed when the FATCA thresholds were met.

☐     Required information returns filed for foreign corporations, partnerships, trusts, and large foreign gifts or inheritances (Forms 5471, 8865, 3520, 3520-A).

☐     Foreign income documented and translated, with exchange rates noted.

Because missing foreign information returns can keep a statute open, this is the area where an unfiled form today can create exposure for years that otherwise would have closed.

6. Records Are Organized and Retrievable

☐     Records stored by tax year and category, in a format you can produce quickly.

☐     Scanned or electronic copies are legible and complete. The IRS accepts electronic

storage of books and records that meets its standards (Rev. Proc. 97-22).

☐     A backup copy exists outside your primary computer or device.

☐     Prior-year returns, including all schedules and supporting workpapers, are retained alongside the records.

7. You Know Who Will Represent You

☐     You know whom to call before you respond to anything.

☐     Your tax professional is authorized to represent you (Form 2848, Power of Attorney

and Declaration of Representative).

☐     You have reviewed the Taxpayer Bill of Rights (IRS Publication 1), including the right to be represented and the right to challenge the IRS's position.

Enrolled Agents, CPAs, and attorneys have unlimited rights to represent taxpayers

before the IRS. With a signed Form 2848, your representative can communicate with the examiner directly — you generally do not need to attend meetings yourself.

Illustrative Example: The Cost of a Missing Log

Consider a self-employed consultant with $180,000 of net Schedule C income who deducted $14,000 of vehicle expenses for a car used roughly 80% for business. During a correspondence audit, the IRS asks for the mileage log. There isn't one — just calendar entries and a rough estimate.

Because vehicles are listed property under Section 274(d), the estimate is not enough, and the full $14,000 is disallowed. In a 24% federal bracket, the approximate result:

Item	Approximate Amount
Additional self-employment tax (15.3% × 92.35% × $14,000)	$1,978
Additional federal income tax (24% × $14,000, less half of the SE tax increase)	$3,123
Accuracy-related penalty (20% under IRC §6662, if it applies)	$1,020
Total before interest and state tax	≈ $6,121

The consultant almost certainly drove those business miles. The deduction was legitimate — it just could not be proven. A free mileage app running in the background would have prevented the entire result. (Figures are simplified and for illustration only; state tax and interest would add to the total.)

Where Exams Tend to Focus

The IRS does not publish its selection formulas, so no list of "red flags" is definitive. That said, the following areas consistently draw scrutiny because they are easy to overstate and hard to substantiate:

•       Unreported income identified through third-party information returns

•       Schedule C businesses with large expenses relative to income, or repeated losses (which can raise hobby-loss questions under IRC §183)

•       Vehicle, travel, and meal deductions

•       S corporation owners taking distributions with little or no salary

•       Large charitable deductions, especially non-cash contributions without qualified appraisals where required

•       Refundable credits such as the Earned Income Tax Credit

•       Foreign accounts, foreign income, and digital asset activity

Being in one of these categories does not mean you will be audited. It means the documentation for these items should be your strongest.

If a Notice Arrives: The First 72 Hours

1.      Don't panic, and don't ignore it. Note the notice number (upper right corner), the tax year, and the response deadline.

2.      Verify it is real. Compare it against the IRS's notice descriptions on IRS.gov, and do not call any phone number you cannot verify independently.

3.      Identify the scope. Is it a CP2000 mismatch, a correspondence exam on specific items, or a request to schedule a meeting? The response strategy is different for each.

4.      Call your tax professional before you respond — including before you call the IRS. An unprepared phone call can expand the scope of the review.

5.      Gather only what is requested. Respond to the specific items listed, with organized, labeled documentation. Do not send your entire file.

6.      Calendar the deadline. If you need more time, request an extension before the deadline passes — not after.

Audit readiness is not about avoiding an audit; it is about making sure that if one happens, it ends quickly and with no change. The work is done months or years before the notice arrives, in the habits you build around recordkeeping today.

1.      Use Q4 to clean up 2026. Reconcile your accounts, fill gaps in your mileage log while trips are still fresh, and document business purpose for this year's travel and meals before memories fade.

2.      Separate business and personal finances now if you have not already. It is the single most effective step toward a clean audit.

3.      Put written documentation in place for S corporations: a reasonable-compensation analysis, an accountable plan, and up-to-date basis schedules.

4.      Review foreign reporting for every open year. If information returns were missed, address them proactively — the options are better before the IRS asks.

5.      Know your retention dates. Don't shred anything tied to an open statute, an asset you still own, or a carryforward still in use.

MKHS Tax Group helps individuals and business owners get audit-ready before a notice ever arrives — and represents clients before the IRS when one does. Reach us at info@mkhstaxgroup.com to schedule a review.