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IRS Notice CP2000

Underreported Income Notice

The IRS believes you didn't report all your income. They've received information (W-2s, 1099s) that doesn't match your return.

Response Deadline
30 days
From the date on the notice
Talk to a Tax Attorney
(877) 829-5267
Free, confidential consultation
Legally reviewed byGregory McCauley Jr., Esq.

Tax Attorney · Villanova University School of Law · Admitted in Delaware, New Jersey, United States Tax Court

Last reviewed

Notice CP2000 in Plain English

CP2000 is not a bill, it is a proposal. The IRS's computer matched a 1099, W-2, or K-1 you didn't fully report and is proposing to add the missing income plus a 20% accuracy penalty. The number on the notice is a starting position — often incorrectly calculated — not a final assessment.

Why the IRS sent you a CP2000

  • A 1099-NEC, 1099-K, 1099-B, or W-2 posted to your SSN that isn't on your return.

  • You reported the income but on the wrong line (e.g., 1099-MISC royalties on Schedule E instead of Schedule C).

  • A brokerage 1099-B reported gross proceeds without cost basis and the IRS is treating the entire sale as gain.

  • Cryptocurrency exchange reports don't match transaction basis you tracked separately.

What Happens If You Ignore Notice CP2000

If you don't respond, the IRS will assess additional taxes, penalties, and interest automatically.

Every day you wait, penalties compound, interest accrues, and your options shrink. The IRS does not negotiate well with silence — they escalate.

What To Do About Notice CP2000

Review the proposed changes. You can agree, partially agree, or disagree. We can help you respond properly.

  1. 1

    Never sign the response form until you've reconciled every line — the CP2000 is wrong or partially wrong in roughly one out of three cases.

  2. 2

    For 1099-B mismatches, provide cost-basis records; this alone routinely reduces the proposed assessment by 60%+.

  3. 3

    For 1099-K mismatches (payment apps), separate reimbursements and personal transfers from actual business income.

  4. 4

    If the underlying income is real, respond with an amended return calculation showing the correct additional tax — do not just accept their number.

  5. 5

    Always dispute the 20% accuracy penalty separately with a reasonable-cause explanation; it is rarely automatic if properly rebutted.

A Senior Tax Attorney's Take on CP2000

CP2000 is one of the most negotiable notices the IRS issues. The team that generates it is separate from Collections, and their goal is closing the file — not maximizing the assessment. A clean, well-documented written response inside the 30-day window frequently zeros out the proposed tax entirely.

Call (877) 829-5267

Costly Mistakes People Make With Notice CP2000

  • Signing the CP2000 agreement page without checking basis on stock, crypto, or real-estate sales.

  • Missing the deadline and losing the right to a pre-assessment reply — the case then jumps to Notice of Deficiency territory.

  • Amending the return during a CP2000 review — this can confuse the automated system and delay resolution by 6 months.

IRS Notices Related to CP2000

These are the notices the IRS most often sends before, after, or alongside a CP2000. Read the related ones to understand where you are in the collection sequence.

Primary Sources & Authority

We cite the underlying IRS publications and statutes so you can verify everything on this page.