Warning - Attention Needed

IRS CP11 Notice

Changes to Your Tax Return

IRS made changes that result in additional tax due

What is CP11? The CP11 notice means the IRS made changes to your tax return that result in you owing more money than you originally calculated.

What This Notice Means

The CP11 notice means the IRS made changes to your tax return that result in you owing more money than you originally calculated. This could be due to math errors, incorrect credits or deductions, or other adjustments the IRS made to your return.

Why You Received This Notice

1
Math errors were found on your tax return
2
You claimed credits or deductions you did not qualify for
3
The IRS adjusted your withholding or estimated tax payments
4
You reported income incorrectly

Important Deadline

The date is printed on your notice. The IRS states no number of days on the CP11 page. This one matters more than most: the IRS states that if you do not contact it by the date shown on your notice, you lose formal rights to have the changes reversed and your right to appeal to the U.S. Tax Court. It also states that if you contact it and send supporting documentation after that date, it will still consider that information and may reverse the changes if it agrees with you.

What You Should Do

Review the changes carefully and compare to your original return
If you agree with the changes, pay the balance by the due date
If you disagree, gather documentation and respond within 60 days
Contact the IRS if you need clarification on the changes
Keep copies of all correspondence

Resolution Options That May Help

Payment Plan

Taxpayers with steady income who can afford monthly payments

Penalty Relief

Situations where the same return type was filed on time for the prior three years and no penalty was assessed in that window — the timely compliance history the IRS tests for administrative relief

What NOT to Do

Do NOT ignore the notice even if you disagree
Do NOT assume the IRS is always correct without verification
Do NOT wait until the deadline to respond if disputing
Do NOT pay without reviewing if you believe there is an error

Frequently Asked Questions

What do I lose if I miss the date?

The trigger is contact, not paperwork. The IRS states that if you do not contact it by the date shown on your notice, you lose formal rights to have the changes reversed and your right to appeal to the U.S. Tax Court. But it also states that if you contact it and send supporting documentation after that date, it will still consider that information and may reverse the changes if it agrees with you. So call by the date even if your records are not yet assembled.

Can I dispute a CP11 notice?

Yes. If you believe the IRS made an error, you can dispute the changes in writing with supporting documentation. Work from the date printed on your notice — the IRS states no number of days on the CP11 page.

What if I cannot pay the amount on CP11?

If you cannot pay in full, you can request an Installment Agreement to pay over time, or explore other resolution options like an Offer in Compromise where IRS conditions are met.

Need Help With This Notice?

Use our free tools to understand your options and connect with professionals who can help.

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Recommended Next Steps

Use our calculator to determine payment options if you owe
Consider an Installment Agreement if you cannot pay in full
File a formal dispute if you believe the changes are incorrect

Sources and last reviewed

Understanding your CP11 notice — Internal Revenue Service, retrieved 2026-08-20

Sourced to primary IRS materials and editorially reviewed on 2026-08-20. Not reviewed by a tax professional. Not tax advice. This page explains a notice in general terms and is not tax or legal advice about your situation. Always use the dates and instructions printed on the notice you actually received. Report a correction.