Tax · United States
IRS Notice CP2000 — proposed changes to your tax return, not a bill
A CP2000 means income information from employers, banks or brokers does not match your tax return, and the IRS proposes changes — usually more tax. It is not a bill and not an audit; a response agreeing or disagreeing is expected.
How serious: needs actionAlso called: CP2000, underreporter notice, notice of underreported income, Automated Underreporter (AUR) notice
The IRS sends a CP2000 when income or payment information it received from third parties — employers, banks, brokers — does not match what was reported on your tax return. The notice proposes changes to the tax, usually an additional amount due.
It is not a bill and not an audit. The notice itself says so: 'This notice isn't a bill'. It shows a side-by-side comparison of what you reported versus what third parties reported, and includes a Response form to sign.
The expected reaction is a response — agreeing with the proposed changes, disagreeing with them, or agreeing in part. The Response form exists for exactly that.
Who sends it
The Internal Revenue Service (IRS) — the United States federal tax authority, part of the Department of the Treasury.
The code 'CP2000' is printed in the top corner, with a headline like 'Proposed changes to your tax return' or 'Proposed amount due'. Inside is a side-by-side comparison of what you reported versus what third parties reported, plus a Response form to sign. The notice states 'This notice isn't a bill'.
The deadline
'Respond within 30 days of the date of the notice or 60 days if you live outside the United States' (IRS Tax Topic 652); the exact due date is printed on the notice
The response window is 30 days from the date printed on the notice — 60 days for recipients living outside the United States. The exact due date is printed on the notice itself.
If you do nothing
Silence does not count as agreement, and it does not make the case disappear. If the IRS does not hear back by the response date, it sends a Statutory Notice of Deficiency (CP3219A / Letter 3219), which starts a strict 90-day window to petition the U.S. Tax Court. After that, the proposed tax is assessed and billed.
How it escalates
- 01A Statutory Notice of Deficiency (CP3219A) is issued.
- 02If no Tax Court petition is filed within 90 days (150 days if the notice is addressed outside the US), the IRS assesses the proposed changes and sends a bill, with interest and applicable penalties.
- 03The unpaid bill then enters the collection sequence: reminder notices, a Notice of Federal Tax Lien, CP504, then a final notice of intent to levy and levy of wages and accounts.
Common questions
Is a CP2000 a bill?
No. The notice itself states 'This notice isn't a bill'. It proposes changes to the tax based on a mismatch with third-party information, and expects a response.
Is a CP2000 an audit?
No. It is an automated comparison of your return against income and payment information the IRS received from third parties such as employers, banks and brokers.
Does staying silent mean agreeing?
No. Silence moves the case to a Statutory Notice of Deficiency, which opens a strict 90-day window to petition the U.S. Tax Court — after that, the proposed tax is assessed and billed.
What if only part of the proposed change is right?
Form 1040-X can be filed with 'CP2000' noted on top, together with the Response form, to reflect partial agreement or additional corrections.
Sources
Facts verified against the sources below on 28 August 2026.