First 30 Days After an IRS Audit: A Local CPA's Checklist for Taxpayers

How the IRS Selects Returns for an Audit

Most returns get flagged by a computer, not a person. The IRS uses a scoring system called DIF (Discriminant Information Function) that compares your return against statistical norms for similar income levels and business types. A return that scores high on DIF gets a second look from a human examiner before anything moves forward.

Beyond DIF scoring, the IRS runs a few other selection methods:

Information matching: your return gets compared against 1099s and W-2s employers and clients already filed, and a mismatch triggers an automatic notice.
Related examinations: if a business partner, investor, or vendor gets audited, your connected return can get pulled in too.
Compliance projects: the IRS sometimes targets specific industries or issues, like cash-heavy businesses or a particular deduction that’s been widely abused.

Common red flags include home office deductions that seem out of proportion to income, unusually large charitable gifts, consistent business losses year after year, and round numbers that suggest estimation rather than record-keeping. None of this means you did anything wrong. Publication 5146 is explicit that being selected does not necessarily indicate an error, and a large share of examined returns close with no changes at all.

Correspondence, Office, and Field Audits: Which One Did You Get?

The letter itself tells you which type of audit you’re facing, and each one comes with a very different level of intensity.

Correspondence audits happen entirely by mail and usually focus on one or two specific items, like a mortgage interest deduction or a claimed dependent.
Office audits require an in-person meeting at an IRS office, typically covering a handful of line items with more back-and-forth than a simple mail exchange.
Field audits send an agent to your home or business and dig into your full financial picture, reserved mostly for business returns with more complexity.
CP2000 notices aren’t technically audits at all. They’re automated notices flagging a mismatch between your return and third-party reporting, and they can often be resolved with a written response rather than a sit-down meeting.

Publication 3498 breaks down all three formal audit types in detail, and Taxpayer Advocate Service guidance walks through what an in-person interview actually looks like. Most individual and small-business audits never escalate past the correspondence stage.

The Audit Timeline: From First Letter to Final Decision

The initial notice tells you three critical things: the tax year under review, the specific items in question, and your deadline to respond. That deadline is usually around 30 days, though extensions are often available if you ask before the clock runs out rather than after.

Here’s how a typical audit unfolds:

Notice arrives by mail. Verify it’s real (check the notice number against the IRS audits page) and read every line before doing anything else.
You respond with documentation. This is where organized records save you weeks, sometimes months.
The examiner reviews and may request more information. A second or third document request isn’t unusual for anything beyond a simple correspondence audit.
You receive a determination. Either the IRS accepts your explanation, proposes changes, or issues a report you need to respond to.
You agree, negotiate, or appeal. This is the fork in the road that decides how much longer things drag on.

Duration varies enormously by audit type. Correspondence audits often close within three to six months when you respond on time. Office audits tend to run several weeks to a few months. Field audits, given their scope, can stretch past a year.

If the IRS proposes changes and you don’t respond, you’ll get a 30-day letter first, offering a window to request an Appeals conference. Ignore that, and a 90-day statutory notice of deficiency follows, which is your last chance to petition Tax Court before the IRS can assess the tax. Separately, the standard statute of limitations gives the IRS three years from your filing date to audit a return, though that window extends if income is substantially underreported.

Gathering Documents Without Losing Your Mind

The IRS is specific about what it wants, and vague, disorganized records are the single biggest reason audits drag on longer than they need to.

Pull together whatever applies to the flagged items:

Receipts and invoices for claimed deductions
Bank and credit card statements covering the audit year
Canceled checks or electronic payment confirmations
Payroll records if you have employees
1099s and W-2s
Mileage logs for vehicle deductions

Match each document to the exact line item mentioned in the notice, not your whole tax return. A short cover letter or index that says “Item 3 corresponds to Documents A through F” saves an examiner time and reduces the odds they ask for more than the original request.

Pro Tip: Never mail original documents. The IRS explicitly recommends sending copies and keeping the originals, along with proof of delivery, in case anything gets lost in transit.

If you’re dealing with a large volume of records, ask the examiner directly whether they’ll accept a secure electronic submission. Many will, and it beats printing a filing cabinet’s worth of paper. If your books are already digitized through a system like Xero, pulling a clean report by category takes minutes instead of days.

Your Rights and How Representation Works

The Taxpayer Bill of Rights gives you real protections during an audit. Knowing them changes how the whole process feels.

The right to professional treatment. The examiner has to be courteous and can’t harass you.
The right to privacy, meaning the IRS can’t dig into anything beyond what’s relevant to the items under review.
The right to representation. You can have a CPA, enrolled agent, or attorney speak for you, and you don’t have to attend meetings yourself.
The right to appeal nearly any decision within the IRS system before it ever reaches a court.

To let someone represent you, you’ll file Form 2848, which grants full power of attorney to speak with the IRS on your behalf, or Form 8821, which only authorizes someone to view your tax information without speaking for you. Remember: the IRS makes first contact by mail only, never by phone or email, so any call claiming to be an “IRS agent demanding immediate payment” is a scam. Bringing in a CPA or enrolled agent tends to make the most sense once a field audit is involved or the dollar amount at stake is significant enough that a mistake in your response could be costly.

What Happens After the Examiner Proposes Changes

Once the audit wraps up, you’ll get a report with the examiner’s findings, and what you do next depends entirely on whether you agree.

If you agree: sign the report (usually Form 4549), arrange payment in full, or set up an installment agreement if you can’t pay the full balance right away.
If you disagree: request an informal conference with the examiner’s manager first. It’s often the fastest path to a resolution.
If the manager conference doesn’t resolve it: file a formal protest with the IRS Appeals office, which is independent from the examination division and often more willing to negotiate.
If Appeals doesn’t work: once you receive the 90-day notice of deficiency, you can petition Tax Court, but that step generally calls for legal representation.

Most disputes settle at the manager conference or Appeals stage. Very few small-business or individual audits ever reach a courtroom.

What an Audit Actually Costs You (Or Doesn’t)

Every audit closes one of three ways: no change, where the IRS accepts your return as filed; agreed, where you accept the proposed adjustments; or unagreed, where the dispute moves to Appeals or beyond.

If you owe more, interest accrues from the original due date of the return, not from when the audit concluded, and penalties for underpayment or negligence can add another 20% or more on top of the tax owed, though penalty abatement is sometimes available if you have reasonable cause. If the audit actually finds you overpaid, which happens more often than people expect, the IRS issues a refund, typically within a few weeks of the final determination. And remember that three-year statute of limitations: once it expires, the return is generally closed for good, barring fraud or a substantial income omission.

How Tolliver Bookkeeping and Tax Handles Audits (And Prevents Them)

Representation means someone else absorbs the back-and-forth with the examiner. Tolliver Bookkeeping and Tax files Form 2848 to communicate directly with the IRS, negotiates proposed adjustments, and handles Appeals filings when a dispute doesn’t resolve at the first level.

Prevention matters just as much. Most audit triggers trace back to sloppy books: expenses coded to the wrong category, 1099 totals that don’t match what a client filed, or reconciliations that never happened. Consistent monthly bookkeeping closes those gaps before a computer ever flags your return.

Tolliver has served Kern County businesses for over two decades, works exclusively as a Xero Silver Partner, and handles document exchange through a secure client portal. A first consultation typically covers your audit letter, recent tax returns, and whatever records the notice specifies.

An Editorial Take: The Myths That Make Audits Scarier Than They Should Be

The biggest myth is that getting audited means you’re suspected of fraud. It almost never does. Most audits trace back to a mismatched 1099 or a deduction that scored high on a statistical model, not a hunch that someone is cheating.

The second myth is that silence is a safe strategy. It isn’t. Deadlines are real, and the taxpayers who struggle most are the ones who wait, hoping the letter goes away. Read it, organize your documents, and if the numbers get complicated, get someone in your corner sooner rather than later.

— Tolliver Team

Get Ahead of an Audit Instead of Reacting to One

If you’ve already received a letter, IRS Representation from Tolliver Bookkeeping and Tax puts a professional between you and the examiner from the first phone call to the final resolution. The stronger position is to maintain accurate records and tax filings to minimize audit risk.

That’s where monthly bookkeeping and business tax preparation do the real work. Coordinating bookkeeping and tax services under one roof helps catch miscoded expenses early, reducing the risk of being flagged by the IRS later. Some firms offer Xero migration at no cost and provide secure client portals for document sharing instead of relying on email.

If you’re holding an audit letter right now, bring it to a consultation along with your last two years of returns and whatever records the notice lists. If you’re not under audit but want to stay that way, request a consultation and get your books reviewed before tax season, not after a notice arrives.

Where to Verify the Rules Yourself

The IRS audits page is the starting point for confirming any notice is legitimate. Publication 3498 walks through the full examination process and appeal rights, while Publication 5146 explains selection methods in more depth for employment tax returns specifically. The records request page lists exactly what documentation examiners typically want, and Taxpayer Advocate Service guidance covers what an in-person interview involves. Keep Form 2848 and Form 8821 on hand if you plan to authorize representation.

This article is general information, not a substitute for advice from a qualified financial advisor. Consult a qualified financial professional about your own circumstances before acting on anything here.

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FAQ

How Long Does an IRS Audit Take?

It depends on the type. Correspondence audits often close in three to six months when you respond promptly, office audits run several weeks to a few months, and field audits can take a year or longer given their broader scope.

What Actually Triggers an IRS Audit?

Most audits start with a high DIF score, a computer-generated statistical comparison against similar returns, or an automatic mismatch between your return and a 1099 or W-2 an employer already filed. Unusually large deductions relative to income and cash-intensive business models also draw closer scrutiny.

Am I in Trouble If I Get Audited?

Not automatically. Selection for an audit does not mean the IRS suspects fraud. It usually just means a specific item on your return scored differently than expected, and many audits close with no change at all once you provide documentation.

How Likely Am I to Be Audited if I Make Less Than $75,000 a Year?

Audit rates for lower and moderate income filers are historically low compared to very high earners and complex business returns, though the IRS doesn’t publish a single fixed percentage tied to that income level. If you do get a notice despite modest income, it’s most often tied to a specific mismatch rather than your income bracket itself.

Can I Have Someone Represent Me During an Audit?

Yes. A CPA, enrolled agent, or tax attorney can speak to the IRS on your behalf once you file Form 2848, and firms like Tolliver Bookkeeping and Tax handle that communication directly so you don’t have to.