IRS notice decoder
IRS Notice CP11: the IRS changed your return and you owe
A CP11 says the IRS found what it believes is a miscalculation on your return, corrected it, and as a result you now owe a balance. This is a math error notice, and it carries a specific right: if you contact the IRS within 60 days of the notice date, it will reverse the change without requiring you to pay first. Miss that window and you generally must pay, then file a claim for refund to contest it.
General information, not tax or legal advice. Deadlines and dollar figures below reflect what the IRS publishes and can change; the controlling dates are the ones printed on your own notice. ClearChoiceRadar is not affiliated with the IRS or any government agency.
What a corrected return triggers
Why you got it
The IRS reviewed your return and concluded there was a math or clerical error, for example a miscalculated credit, a transposed figure, or an entry that did not add up. It corrected the return, and the correction changed what you owe, producing a balance due of five dollars or more.
A math error correction is different from an audit. The IRS can make this kind of change and assess the extra tax without first sending a formal deficiency notice. That is exactly why the response window below matters.
The right most people miss
You have 60 days to reverse it without paying first
If you contact the IRS within 60 days of the date on the notice, it will reverse the change to your account so the matter can be examined properly. If you do not respond within 60 days, the assessment stands: you forfeit the right to have it reversed without payment, and you lose the ability to take the dispute to Tax Court before paying. At that point contesting it means paying the tax and filing a claim for refund. The 60 day window comes from the math error rules in Internal Revenue Code section 6213.
Agree or disagree
You agree with the change
Pay the balance by the date on the notice, or set up a payment plan if you cannot pay in full.
How IRS payment plans work →You disagree
Contact the IRS at the number on the notice within 60 days, with documentation supporting your original figures. Ask that the change be reversed. If it cannot be resolved, the case moves to a full review with appeal rights.
What the balance costs while it sits
- Interest
- accrues on the new balance from the return's original due date
- Late payment penalty
- 0.5% per month or part of a month if not paid by the notice date, up to a cap of 25%
If you think the correction is wrong, use the 60 day window first, because it is the only way to contest the change without paying it.
CP11 questions
What is a CP11 notice?
A CP11 tells you the IRS corrected what it believes was a miscalculation on your return and, as a result, you now owe a balance. It is a math error notice, which the IRS can issue and assess without first sending a formal deficiency notice.
How long do I have to dispute a CP11?
You have 60 days from the date on the notice to contact the IRS and request that the change be reversed without paying first. If you miss that window, you generally must pay the tax and then file a claim for refund to contest it, and you lose pre-payment Tax Court access.
What if I miss the 60-day window on a CP11?
The correction stands. You forfeit the right to have it reversed without payment and lose the ability to petition Tax Court before paying. To contest it after that, you generally pay the balance and file a claim for refund with documentation supporting your original figures.
Can I set up a payment plan for a CP11 balance?
Yes. If you agree with the change but cannot pay in full, most individual balances qualify for an installment agreement. Interest and a reduced late payment penalty continue while you pay.
Sources: IRS: Understanding your CP11 notice, IRS Taxpayer Advocate Service: Notice CP11, Balance Due. The deadline that governs your case is the one printed on your notice.
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