CP2000: the IRS says your income does not match

A CP2000 says that income or payment information the IRS received from third parties does not match what your return reported, and it proposes a change as a result. It is not an audit and it is not a bill; it is a proposal with a response form and a deadline.

What it actually is

Employers, banks, brokers and payment platforms send the IRS copies of what they sent you. A computer compares those documents against the return you filed. When the totals disagree, the system drafts a notice showing what it has, what you reported, and the tax it proposes on the difference.

Nobody has looked at your books. The proposal is arithmetic run against documents, which means it is often right, sometimes right about the income but wrong about the tax, and occasionally wrong from the start because a document was filed against your Social Security number in error.

The tax the notice proposes is usually calculated as though the income had no offsetting basis, no offsetting expense, and no exception. That assumption is where most successful responses live.

The usual causes

• A 1099 you forgot. A short contract, a side job, a savings account at a bank you no longer use. The payer reported it; your return did not.
• A 1099-K from a payment platform. Card and app settlements are reported gross, before fees and before refunds to customers, so the reported figure is often larger than what you actually kept.
• A rollover reported as a distribution. A retirement account moved between custodians produces a 1099-R showing a full distribution. If the return did not show it as a rollover, the match reads it as taxable income.
• Stock or crypto sales with no basis. A broker reports the proceeds of a sale. If the return did not report the sale, the notice generally treats the entire proceeds as gain.
• Two versions of the same document. A corrected 1099 that was issued after you filed, or a document issued twice, can show up as income counted once too often.

How to answer

Every CP2000 arrives with a response form. That form, not a phone call and not a new return, is the response.

If you agree, sign and return the form the way the notice directs, and pay what you can with it. Agreeing does not require an amended return unless you have other income, credits or expenses to report that the notice does not cover.

If you disagree, say so on the response form and explain why, in writing, with copies of the documents that support you. Brokerage statements showing basis, the Form 5498 or account statement showing a rollover, the platform report reconciling gross settlements to your actual receipts, a letter from a payer confirming a document was issued in error.

If you agree with part of it, that is a normal answer and the form allows it. Mark what you accept, explain what you do not, and attach documents for the part you dispute.

The window, and what runs while it is open

You generally have thirty days from the date on the notice to respond, or sixty days if you live outside the United States. The date printed on your own notice governs.

Interest accrues on any amount that turns out to be due, running from the original due date of the return rather than from the date of the notice, and penalties may apply. Paying the proposed amount within the response window generally stops further interest, and possibly further penalties, from accruing. That is a real consideration if you expect to agree in the end.

If the window closes with no response, the IRS generally moves on to a statutory notice of deficiency, which is a different document with a different clock and fewer easy exits. Responding late is better than not responding, and responding on time is better than either.

Amending is not the answer here

The instinct to file Form 1040-X is understandable and usually wrong for a CP2000. The notice already contains the mechanism to change the year in question, and a second return filed into the middle of it tends to create two open matters instead of closing one.

File an amended return alongside a CP2000 only when the notice is correct and you have other things to report that it does not address. In that case the amended return goes with the response form rather than instead of it, and the IRS asks that it be marked to show which notice it belongs to.

Keep everything you send, and keep the notice itself. If a later letter arrives about the same year, the first useful question is what you already told the IRS and when.