Tax Relief AnswersIRS Notice CP2000: Unreported Income and How to Respond
The short answer
A CP2000 is a proposed change to your tax return, not a bill. The IRS sends it when income or payment information from third parties (employers, banks, brokers) does not match what you reported. The change can raise your tax, lower it or leave it the same. Reply by the date listed on the notice, saying whether you agree or disagree and attaching documents. Source: IRS, Understanding your CP2000 notice, reviewed July 14, 2026.
What the notice means
| Item | What the IRS page says |
|---|---|
| Why you got it | Third-party income or payment information does not match your return |
| Is it a bill? | "This notice isn't a bill and your response may be required" |
| Deadline | "Reply to the notice by the date listed" |
| If you agree | Complete and sign the response form; you do not need to amend your return |
| If you disagree | State why and include supporting documentation |
| If you do not reply | "We may send another notice and a bill" |
| Paying | Interest accrues until the balance is paid and penalties may apply; a payment plan or Offer in Compromise is available if you cannot pay in full |
| More detail | Publication 5181, Tax Return Reviews by Mail |
"Does not match" means a payer sent the IRS a form (a W-2, a 1099, a brokerage statement) whose figures do not appear the same way on your return. The notice shows the IRS's figures next to yours, with the payer's name, so you can check each line.
What to do
- Compare each item on the notice with your records for the year named: W-2s, 1099s, brokerage and bank statements.
- If the IRS is right, sign the response form and return it by the date on the notice. Pay what you can and apply for a payment plan for the rest.
- If the IRS is wrong or partly wrong, mark that you disagree, explain each item in a short letter, and attach copies (not originals) of the documents that show it. A stock sale often needs the cost basis the IRS did not have.
- If the income is yours but a deduction or credit offsets it, say so and include the figures.
- Send the response by the method the notice gives, and keep a dated copy.
What this notice does not mean
- It does not mean you have been billed. A bill comes later, and only if you agree or do not respond.
- It does not mean you must file an amended return. The IRS page says you do not need to amend if you agree with the proposal.
- It does not give a fixed number of days. The IRS page says to reply by the date listed on the notice; use that date.
- It does not mean collection has started. No lien or levy follows a CP2000 directly; those come only after a balance is assessed and the collection notice sequence begins with a bill.
Most CP2000 replies are a signed form and a few photocopies. If the amounts are large or you disagree, a Low Income Taxpayer Clinic can help for free if you qualify; otherwise a licensed professional (enrolled agent, CPA or attorney) can respond for you.
FAQ
Is a CP2000 an audit?
The IRS page describes it as a notice of proposed changes based on third-party information, covered in its Publication 5181 on tax return reviews by mail.
Do I have to pay the amount on a CP2000?
Not yet. It is a proposal; the IRS sends a bill after you agree or after it resolves the mismatch without your reply.
What if I agree but cannot pay?
Sign the response form and apply for a payment plan or, if you qualify, an Offer in Compromise, as the IRS page suggests.
What happens if I ignore it?
The IRS page says it may send another notice and a bill; interest accrues and penalties may apply.