All notices › Return Adjustment
IRS CP11: Math Error Correction — Balance Due
Straight answer: A CP11 means the IRS corrected a calculation error on your return AND the correction results in you owing money. It shows the change and the new balance due.
How many days do I have to respond to a CP11?
60 days from the date printed on the notice (not the day you opened it). Pay by the due date on the notice to limit interest. You have 60 days to dispute the correction itself.
Your response deadline is approximately — days from today.
What should I do right now?
- Verify the IRS's math against your return — corrections are usually right, but not always.
- If you agree, pay or set up a payment plan.
- If you disagree, contact the IRS within 60 days to request reversal.
The costly mistake people make with a CP11
Paying a wrong correction because it looks official. The 60-day window makes disputes cheap; after it closes they're expensive.
Do I need professional help with a CP11?
Needed only if the amount is large or involves disputed credits or dependents.
Want a professional to look at your CP11?
Tell us what you received and we'll connect you with a licensed tax resolution professional for a free case review. No obligation.
Get my free case review →