If you've got an IRS letter on your desk right now, you have a decision to make, and the clock matters. I'm Darrin Mish. I've spent 32 years helping people with exactly this kind of situation. Here's what you should do.<\/p>\n
You opened an envelope from the IRS and the number at the bottom made your stomach drop. Before you do anything else, understand this: a CP2000 is not a bill, and it is not an audit. It is a proposal. The IRS is telling you what it thinks you owe based on paperwork somebody else filed about you, and it is asking whether you agree.<\/p>\n
You are allowed to say no.<\/p>\n
That distinction matters more than almost anything else on the page, because the taxpayers who get hurt by CP2000 notices are rarely the ones who owed the money. They are the ones who assumed the IRS had already decided, and did nothing.<\/p>\n
Every year the IRS receives information returns from third parties. Employers file W-2s. Banks file 1099-INTs. Brokerages file 1099-Bs. Partnerships file K-1s. In fiscal year 2025, the IRS took in more than 4.4 billion of these documents.<\/p>\n
A computer matches those documents against what you reported on your return. When the numbers do not line up, the system flags the difference and the Automated Underreporter program, which the IRS calls AUR, opens a case. If a tax examiner reviews it and still has questions, you get a CP2000.<\/p>\n
The scale is worth sitting with. In fiscal year 2025 the IRS closed 987,460 AUR cases and assessed roughly $5.9 billion in additional tax and interest. Over the same period it closed 441,578 audits of individual income tax returns. The matching program reaches more than twice as many individual taxpayers as actual audits do, and it runs on 1,428 full-time equivalent positions.<\/p>\n
Run the division and the average closed case produced just under $6,000, interest included. This is a volume operation.<\/p>\n
No. And this is not my characterization, it is the government’s.<\/p>\n
Revenue Procedure 2005-32 specifically provides that contacting a taxpayer to verify a discrepancy between a return and an information return is not an examination, an inspection, or a reopening. The Internal Revenue Manual instructs AUR examiners, in capital letters, to “AVOID ‘AUDITING’ RETURNS,” and explains why: every return in the AUR inventory was already screened for audit potential and was not selected.<\/p>\n
The IRS says as much in its own notice language. One of the paragraphs it can print on a CP2000 reads: “This isn’t an audit; your return may be subject to an examination later.”<\/p>\n
Read that second clause, though. Not an audit now. Not immune forever. A CP2000 does not convert into an audit, but a response that raises new questions can put your return in front of human eyes that were never going to look at it. That is an argument for answering carefully, not for panicking.<\/p>\n
Here is the honest answer, and I want to be precise because there is a lot of nonsense circulating on this question. The IRS does not publish an error rate for CP2000 notices. The Data Book reports how many cases closed and how much was assessed. It does not report how many closed with no change. If you see a specific percentage quoted online, ask where it came from, because the number making the rounds right now traces back to a single article citing a government report that does not appear to exist.<\/p>\n
So no, I am not going to hand you a statistic. What I can hand you is better: the IRS’s own operating manual, which devotes substantial space to the many ways these notices go wrong.<\/p>\n
The IRS maintains something called the Payer Agent file. It is a running list of information returns that have been, in the manual’s words, “verified as erroneously filed or processed or determined potentially fraudulent.” An entire IRS system exists to track employers and payers who report bad numbers about people.<\/p>\n
The manual also flags these recurring problems:<\/p>\n
And then there is my favorite document in the whole manual. The IRS keeps a library of pre-written paragraphs to drop into notices. CP Paragraph 88 begins: “Please disregard the previous CP2000 notice we sent you, the proposed tax change was incorrect. We apologize for any inconvenience this may have caused.”<\/p>\n
They have a form letter for being wrong. They needed one often enough to write it down.<\/p>\n
This is the part most people miss, and it is the single most useful thing in this article.<\/p>\n
The Internal Revenue Manual tells AUR examiners that “when evaluating a taxpayer’s explanation for unreported income it isn’t necessary to verify everything the taxpayer says.” It goes further: “The taxpayer’s explanation will generally be taken at face value, including schedules of expense submitted by the taxpayer to offset unreported income.” The examiner is then told to consider whether the explanation is reasonable.<\/p>\n
You are not walking into Tax Court. You are writing to a tax examiner who has been instructed to weigh whether your explanation makes sense and to stay confined to the issues raised on the notice. A clear letter with organized documents resolves an enormous number of these cases.<\/p>\n
If your explanation covers the full amount in question, the manual directs the examiner to close the case with no change to your original tax liability. That outcome has its own process codes. It happens every day.<\/p>\n
You have 30 days from the date on the notice. Not from the day you opened it. The due date is printed on page one.<\/p>\n