IRS CP2501 Notice
Underreporter Inquiry — Income Doesn't Match
The step before a CP2000. The IRS states this isn't a bill, but you must respond.
What is CP2501? CP2501 tells you that income or payment information the IRS received from third parties -- employers, financial institutions -- doesn't match what you reported on your tax return.
What This Notice Means
CP2501 tells you that income or payment information the IRS received from third parties -- employers, financial institutions -- doesn't match what you reported on your tax return.
This is an earlier, less formal step than a CP2000. The IRS states this difference "may increase or decrease your tax or may not change it at all," and the notice does not itself propose a specific dollar figure the way a CP2000 does. The IRS states plainly: "This notice isn't a bill, but you must respond."
Why You Received This Notice
- 1The IRS states income or payment information from third parties doesn't match the information you reported.
Important Deadline
The IRS states to reply on the letter's response form and return it by the date listed on the notice. It does not publish a general number of days on the CP2501 page -- use the date on the response form you received.
What You Should Do
- Review the entire notice and follow its instructions.
- Reply using the response form by the date listed.
- If you disagree, the IRS states to include a signed statement explaining your disagreement and documentation supporting your claim.
What NOT to Do
- Do NOT treat this as a bill. The IRS explicitly states it is not one -- but also explicitly states you must respond.
- Do NOT assume the mismatch means you owe more. The IRS states the difference may increase, decrease, or not change your tax.
Need Help With This Notice?
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Recommended Next Steps
- Locate the third-party statements (W-2s, 1099s) the notice references and compare them to what you reported.
- Prepare a written response either agreeing or explaining the disagreement with documentation.
What this page does not say
- The page does not state what happens if you do not respond by the date listed.
- The page does not contain a dedicated FAQ section.
Sources and last reviewed
- Understanding your CP2501 notice — Internal Revenue Service, retrieved 2026-08-24
Sourced to primary IRS materials and editorially reviewed on 2026-08-24. Not reviewed by a tax professional. Not tax advice. This page explains a notice in general terms and is not tax or legal advice about your situation. Always use the dates and instructions printed on the notice you actually received. Report a correction.