IRS letters › CP11
Notice CP11
The IRS corrected your return, and you owe
The IRS found a math error or a mistake in a credit on your return, recalculated your tax, and now shows a balance.
What it means
A "math error" notice. It covers simple mistakes, such as an addition error, a credit claimed without the required Social Security number, or a figure copied wrong. The IRS can correct these without the usual deficiency procedure, but you have 60 days to object.
What to do
- Compare the IRS's figures with your return, line by line.
- If you agree, pay by the date shown, or set up a payment plan.
- If you disagree, call or write within 60 days. The IRS must then reverse the change and use the formal deficiency procedure if it still thinks you owe.
Don't
- Don't let the 60 days pass if you disagree. After that you lose the right to have the change reversed automatically.
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Is it really from the IRS?
The IRS starts contact by mail. A real notice has a notice number and your tax year, and you can see it, with any balance, in your IRS online account. The IRS never demands payment by gift card, crypto or wire transfer, and never threatens arrest. If in doubt, call the IRS using a number from IRS.gov, not one from the letter.
The law behind it
Free help
The Taxpayer Advocate Service is an independent part of the IRS that helps when a problem isn't being resolved (Form 911, or 877-777-4778). Low Income Taxpayer Clinics represent people for free or a small fee, many in Spanish and other languages.
Other letters
General information, not tax or legal advice. Always follow the dates and instructions printed on your own notice.