Is a CP2000 the same as an audit?

No. A CP2000 is not a formal audit. It is generated automatically by the IRS Automated Underreporter (AUR) computer system — not by a human auditor — when it detects a mismatch between your return and third-party information. An audit involves an IRS examiner reviewing your return in detail. A CP2000 is a narrower, automated process that can often be resolved with documentation in writing, without the scope or complexity of an audit.

What happens if I ignore a CP2000?

If you do not respond by the deadline (typically 30 days from the notice date), the IRS will assume you agree with the proposed changes and issue a Statutory Notice of Deficiency (CP3219A) — the 90-day letter. At that point, the proposed changes become an assessed tax debt unless you petition the U.S. Tax Court within 90 days. Ignoring a CP2000 also causes interest to continue accruing on any proposed balance, and may result in a 20% accuracy-related penalty.

Should I file an amended return in response to a CP2000?

Generally no — do not file an amended return (Form 1040-X) in response to a CP2000 unless the IRS specifically instructs you to. Instead, use the response form included with the notice to agree, disagree, or partially agree, and attach any supporting documentation. If you agree and have additional items to report (deductions or credits related to the underreported income), the IRS instructs you to complete a Form 1040-X and write 'CP2000' on the top, but only in that specific situation.