Quick answer: A CP11 means the IRS corrected what it considers a miscalculation on your return, and the correction created a balance due. You generally have 60 days to dispute the change if you disagree — after that, contesting it becomes much harder.
Why did I receive a CP11?
The IRS adjusts returns for what it classifies as “math errors” — but that label is broader than arithmetic. Mismatched credits (like the Child Tax Credit or education credits), incorrect estimated payment amounts, and ID-number mismatches all trigger CP11 corrections.
Can the IRS’s correction itself be wrong?
Yes — automated corrections are frequently based on incomplete information. If you respond within the 60-day window, you can require the IRS to reverse the assessment and follow normal procedures, which preserves your appeal rights. Miss the window and the balance stands unless you pursue more difficult remedies.
What should I do right now?
- Note the date on the notice — your 60-day clock runs from it
- Compare the IRS’s figures against your filed return line by line
- Don’t pay simply to make it go away if you believe the correction is wrong
- Get a professional review before the dispute window closes
Disagree with your CP11?
The dispute window is short. A free 15-minute call tells you whether the IRS’s correction holds up — and what to do if it doesn’t.