Getting a letter from the IRS feels alarming. Most of the time, it isn't. The majority of IRS examinations are conducted entirely by mail — a correspondence audit asks you to substantiate one or two specific items by sending documentation. Brian's video walks through how to respond calmly and step-by-step; this companion piece adds the IRS primary-source layer: the 3 audit types, the 30-day window, burden-of-proof reality, your Taxpayer Bill of Rights, and when to call in a professional.
ClearValue Lending is not a CPA, enrolled agent, tax attorney, or tax-relief firm. This article is general tax education about the IRS audit process. It is not personalized tax or legal advice. If you have received an IRS notice, consult a qualified tax professional — an enrolled agent, CPA, or tax attorney — before responding. Nothing here constitutes legal representation or legal advice.
Brian's video above walks through what to do when an IRS audit letter arrives — what the letter likely means, how to read it, and how to respond without panic. This editorial companion adds the IRS primary-source framework: how the IRS classifies audits, the formal response procedures published in Publication 556, your rights under the Taxpayer Bill of Rights, and how to decide whether to handle the correspondence yourself or bring in a professional.
The IRS conducts examinations in three formats. Understanding which type you are dealing with determines how you respond and how much urgency the situation carries.
A CP2000 is not technically an audit, but it arrives like one. The IRS's Automated Underreporter (AUR) system compares income reported on 1099s, W-2s, and other third-party documents against what appeared on your tax return. When it finds a discrepancy, it generates a CP2000 — a proposal to adjust your income, tax, credits, or deductions. It is a proposal, not a bill and not a formal audit finding.
You have 30 days from the notice date to respond (60 days if you live outside the US). If you agree with the proposed change, sign the response form and return it — with or without payment. If you disagree, check the disagreement box, write a brief explanation, and include supporting documentation showing why the income was already reported, was not taxable, or was offset by deductions the IRS did not have on file.
Most IRS letters set a response deadline — typically 30 days from the notice date. The IRS systems are largely automated: when a response deadline passes with no reply, the case advances to the next stage automatically. An unanswered correspondence audit can become an unanswered 30-day letter; an unanswered 30-day letter becomes a Statutory Notice of Deficiency; a Statutory Notice of Deficiency, if not responded to within 90 days, results in a tax assessment that can then be collected.
The IRS does grant extensions in many cases — but you have to ask. Call the number on the notice, explain that you need additional time to gather records, and request an extension before the deadline passes. Extensions are generally granted for correspondence audits; they are not guaranteed, but a proactive call almost always produces a better result than silence.
In an IRS examination, the burden of proof generally rests with the taxpayer. The IRS doesn't have to disprove what you claimed — you have to prove you were right. This is why documentation discipline matters: receipts, bank statements, mileage logs, donation acknowledgment letters, and contract records are the evidence that resolves a correspondence audit quickly.
Before sending anything to the IRS: make photocopies of every document you submit. Send copies only — never originals. The IRS will not return documents you send, and originals are difficult to replace if lost in transit or processing.
The documentation you should already have on file: bank statements for the tax year, receipts for deductions claimed (business meals, equipment, home office), mileage logs for vehicle deductions, charitable donation acknowledgment letters for gifts over $250, and 1099s and W-2s matching what you reported. If you can't locate a receipt, a bank or credit card statement showing the charge may be acceptable as a secondary source — but the stronger the documentation, the faster the case closes.
Most correspondence audits close the same way they start — by mail. The IRS asks for evidence of a specific deduction. You send copies of the receipts. The case closes with no change. The taxpayers who panic and don't respond are the ones who end up with an unwanted assessment they didn't fight.
Not every audit requires professional representation. A simple correspondence audit asking for receipts to back up a charitable deduction is something most taxpayers can handle on their own. But as complexity, dollar amounts, or risk levels rise, professional help pays for itself.
A general rule: if the amount the IRS proposes to assess exceeds what a professional would charge to represent you, hire the professional. If the audit is a straightforward correspondence audit over a deduction you can document with paperwork you have on file, handle it yourself — but don't skip responding.
The IRS is required to inform every taxpayer of their rights under the Taxpayer Bill of Rights. There are 10 of them, codified in IRC §7803(a)(3) and published in IRS Publication 1. Several matter directly in an audit context.
If you go through an audit and disagree with the result, you don't have to accept it. After the examination closes, the IRS sends a 30-day letter proposing changes. You have 30 days to request an appeals conference with the IRS Office of Appeals — an independent body within the IRS that reviews examination decisions.
Appeals is a legitimate and frequently used path. The Office of Appeals operates separately from the examination function, and its role is to resolve disputes without litigation. It is free to use (no filing fee). If you can't resolve the matter through appeals, you may then petition Tax Court — but that step is less common and typically involves attorney representation.
If you believe the IRS is being unresponsive or that the process is taking an unreasonable amount of time, the Taxpayer Advocate Service (TAS) is an independent organization within the IRS that helps taxpayers resolve problems. TAS can intervene when normal IRS channels are stalled. Their website is at taxpayeradvocate.irs.gov.
Self-employed business owners and sole proprietors face higher audit-scrutiny rates than W-2 employees — Schedule C returns with home-office deductions, vehicle deductions, and mixed personal/business expenses are among the most frequently examined. The same recordkeeping discipline that protects you in an audit also strengthens your business funding application: clean books, documented income, and separating personal from business expenses all improve the picture a lender sees. If you're navigating audit concerns alongside business growth, the two issues often have the same root fix — organized, well-documented financials.
Most IRS audit letters and correspondence notices require a response within 30 days of the notice date. CP2000 notices also carry a 30-day response window (60 days if you live outside the US). If you need more time to gather records, call the number on the notice before the deadline and request an extension — the IRS generally grants extensions for correspondence audits. Do not ignore the letter; an unanswered notice escalates automatically. Source: IRS Topic 651; IRS Topic 652.
No — a CP2000 is technically not an audit. It is an automated underreporter notice generated when the IRS's AUR system finds a discrepancy between income reported on W-2s or 1099s and what appeared on your return. It is a proposal to adjust your tax — not a formal audit finding. You can agree (sign and return the response form, with or without payment) or disagree (provide documentation explaining why you believe the original return was correct). If you disagree and the IRS accepts your explanation, the case closes with no change. Source: IRS Topic 652.
Not always. A simple correspondence audit asking you to substantiate one specific deduction with receipts is something most taxpayers can handle by mail on their own. Professional help becomes more valuable when: the dollar amount at stake exceeds what representation costs; the audit expands in scope; the IRS is asking for records you don't have; or there is any suggestion of fraud or significant underreporting. Enrolled agents (federally licensed by the IRS) are often the most cost-effective choice for correspondence and office audits. A tax attorney should be involved if criminal exposure is possible. Source: NAEA — National Association of Enrolled Agents (naea.org).
Missing receipts don't automatically lose your case, but they weaken your substantiation. Common alternatives: bank or credit card statements showing the charge (date, amount, payee), canceled checks, emails confirming purchases, or vendor invoices. For mileage deductions, a reconstructed mileage log — built from calendar entries, GPS history, or appointment records — may be acceptable if it is contemporaneous with the tax year. Document what you can, explain the gap clearly in your response, and let the IRS evaluate. If the gap is large, a tax professional can advise on how courts and the IRS typically treat reconstructed records in similar situations.
Yes, but it is uncommon for individual taxpayers. A field audit involves an IRS examiner visiting your home or business to conduct a comprehensive examination of your records. Field audits are more typical for businesses with complex financial records and are far less common than correspondence audits conducted by mail. If you receive a notice scheduling a field examination, retaining a CPA or tax attorney before the first meeting is strongly advisable — field audits have broader scope than correspondence audits and the in-person dynamic changes the proceeding meaningfully. Source: IRS Publication 556.