Understanding your CP11 notice

Review the “What we changed on your return” section of your notice. For more information about the errors on your return, call us at the number shown in the “Where to find more information”.

• If you disagree, contact us by the date shown on your notice. You can call us or mail your response indicating disagreement. Call us at the toll-free number shown in the “What to do if you disagree with our changes” section of your notice. The fastest way to resolve many return errors is by telephone. Some cases require additional information that you may provide verbally. If we need a missing or corrected form or document, you can fax your documents using either a fax machine or online fax service while on the telephone. Protect yourself when sending digital data by understanding the fax service’s privacy and security policies.
• If you choose to write to us, use the address shown in the “What to do if you disagree with our changes” section of your notice. Include a copy of the notice along with your correspondence or documentation and allow 30-60 or more days for a resolution.

We’ll reverse most changes we made if we increased the amount you owe or if your return requested a refund. You don’t need to provide an explanation or additional documents when you request the reversal, but doing so may help us resolve your case more quickly. If we don’t receive information that supports your original return, we may forward your case for audit, in which case the audit staff will contact you within 6 weeks to explain the process and your rights.

If you don’t contact us by the date shown on your notice, you will lose formal rights to have the change(s) reversed, as well as your right to appeal our decision to the U.S. Tax Court. However, if you contact us and send supporting documentation after that date, we will still consider that information and we may reverse the change(s) to your return if we agree with you.

To avoid interest charges, full pay the amount owed by the due date shown on your notice. If you don't pay in full by that date, interest will accrue on the unpaid balance from the date the return was due.

Yes, you will receive a late payment penalty. You can contact us at the number shown on your notice if you can't pay the full amount shown in your specific notice because of circumstances beyond your control. Contact us by the due date of your notice and depending on your situation, we may be able to remove the penalty. See our Penalty relief page for what information to have available.

You'll need to file a Form 1040-X, Amended U.S. Individual Income Tax Return PDF to make a correction.