IRS Notice CP11: What It Means & What to Do
CP11 means the IRS corrected one or more mistakes on your tax return and you now owe. Learn how to check the change, pay, or ask for a reversal before the deadline.
Written and maintained by Joseph Lancaster, Settlement Officer since January 2013
Published · Checked against IRS sources on
Quick answer
What is an IRS CP11 notice and what should I do?
CP11 means the IRS corrected a mistake on your return and you now owe. If you agree, pay by the date on the notice. If you disagree, contact the IRS by that date to ask for a reversal; missing it ends your formal reversal and Tax Court rights.
Who this applies to: People whose return the IRS corrected for a mistake, creating a balance due.
What can change this answer
- Contact by the notice date to keep reversal and Tax Court rights
- Unsupported reversals may be sent to audit
- Interest accrues from the return due date if not paid in full
Recommended next step
Review what changed, then pay or call the IRS before the date on the notice.
Read the full guideCP11 means the IRS corrected one or more mistakes on your tax return and, as a result, the amount you owe changed. If you agree, pay by the date on the notice. If you disagree, contact the IRS by that date: it says it will reverse most changes that increased what you owe.
Immediate Steps to Take
- 1Read the "What we changed on your return" section of the notice
- 2If you agree, pay by the date shown and correct your own copy of the return (do not send it to the IRS)
- 3If you disagree, call the number on the notice before the date shown
- 4If you cannot pay in full, ask about paying over time
What CP11 means
The IRS sends CP11 when it corrects one or more mistakes on your tax return and that changes the amount you owe. The "What we changed on your return" section explains the change. If you need more detail, call the number in the notice's "Where to find more information" section.
If you disagree: the date on the notice matters
Contact the IRS by the date shown on the notice. The IRS says it will reverse most changes it made if they increased the amount you owe or affected a refund you requested. You do not need to give an explanation or documents to request a reversal, though doing so may help resolve your case faster. If the IRS does not get information supporting your original return, it may send your case to audit, and the audit staff will contact you within 6 weeks.
If you miss the date, the IRS says you lose your formal right to have the change reversed and your right to appeal to the U.S. Tax Court. It may still consider documentation you send later.
If you agree with the change
Pay the amount by the date on the notice to avoid more penalties and interest. If you do not pay in full by that date, the IRS says interest accrues on the unpaid balance from the date the return was due. If you cannot pay in full now, ask about an installment agreement.
Frequently Asked Questions
How do I find out what the IRS changed on my return?
Review the "What we changed on your return" section of the CP11. For more detail, call the number in the "Where to find more information" section.
Can I get the CP11 change reversed?
The IRS says it will reverse most changes that increased the amount you owe if you contact it by the date on the notice. If it does not get information supporting your original return, it may refer the case to audit.
What happens if I miss the CP11 deadline?
You lose your formal right to have the change reversed and your right to appeal to the U.S. Tax Court. The IRS says it may still consider supporting documents you send after the date.
Authority Citations
This content is based on the following official IRS sources. All links open in a new tab.
Information current as of 2026. Tax laws change frequently. Verify with official IRS sources before taking action.
Important information