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Published:   |   Last Updated: August 9, 2023


IRS Issues Math Error Notice – Balance Due

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Notice Overview

The IRS corrected one or more mistakes on your tax return due to a miscalculation.

This notice or letter may include additional topics that have not yet been covered here. Please check back frequently for updates.

What does this mean to me?

The IRS received your individual income tax return and determined you have a balance due. A CP11, Math Error on Return – Balance Due, notice is issued when there is a mistake on your return that resulted in a balance due of five dollars or more.

How did I get here?

You submitted your income tax return with one or more mistakes that needed to be corrected. As a result:

  • The balance due is different from the one you expected, or
  • You have a balance due when you thought you had an overpayment that was to result in a refund.


You must contact the IRS within 60 days of the date of this notice, for IRS to reverse the changes made on your account.

What are my next steps?


Review the notice carefully and compare the changes made to the information on your tax return

It will explain the changes made and why you owe money. Contact the IRS at the toll-free number listed on the top right corner of your notice to find out what changes the IRS made to your tax return.

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Note: Authorized third parties may assist taxpayers

Complete and send the IRS a Form 2848, Power of Attorney and Declaration of Representative, to authorize someone (such as an accountant) to represent you before the IRS. Without a valid Power of Attorney on file, you must be present for any discussions with the IRS and a third party.


If you agree

If you agree with the changes made, no response is required.

  • Pay the amount owed by the date on the notice.

If you are unable to pay the amount owed in full, pay as much as you can to limit penalties and interest. Visit Paying Your Taxes to consider online payment options. If you believe you will be able to pay your balance in full within the extended time frame, you may qualify for a short-term payment plan without paying a user fee. If you need additional assistance, call the IRS at the toll-free number on the top right corner of your notice.

If you need to make payment arrangements if you can’t pay the full amount you owe. You can do this online using the Online Payment Agreement tool.

You may want to correct the copy of your tax return that you kept for your records, but do not send it to the IRS


If you disagree

If you disagree, contact the IRS at the toll-free number listed on the top right corner of your notice or respond by mail to the address on your notice. If you write to the IRS, include a copy of the notice along with your correspondence or documentation.

  • If you contact the IRS within 60 days of the date of this notice, the IRS will reverse the changes made to your account. However, if the IRS requests documentation from you and you can’t provide it or the documentation you provide is not satisfactory, the IRS will forward your case to the Examination department for a formal review of the items in question. Forwarding your case gives you formal appeal rights, including the right to appeal the decision in court. After your case is forwarded, you should be contacted by a member of the Examination staff within five to six weeks to explain the audit process and your rights.

If you don’t contact the IRS within 60 days, you must pay the additional tax, then file a claim for refund before the IRS will consider reversing the changes. You must submit the claim for refund within three years from the date you filed the tax return, or within two years from the date of your last payment for this tax, whichever is later.

If you don’t contact the IRS within the 60-day period, you’ll lose your right to appeal the decision before payment of tax.

Where can I get additional help?

Understanding your notice or letter

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If you still need help

The Taxpayer Advocate Service is an independent organization within the IRS that helps taxpayers and protects taxpayers’ rights. We can offer you help if your tax problem is causing a financial difficulty, you’ve tried and been unable to resolve your issue with the IRS, or you believe an IRS system, process, or procedure just isn’t working as it should. If you qualify for our assistance, which is always free, we will do everything possible to help you.

Visit www.taxpayeradvocate.irs.gov or call 1-877-777-4778.

Low Income Taxpayer Clinics (LITCs) are independent from the IRS and TAS. LITCs represent individuals whose income is below a certain level and who need to resolve tax problems with the IRS. LITCs can represent taxpayers in audits, appeals, and tax collection disputes before the IRS and in court. In addition, LITCs can provide information about taxpayer rights and responsibilities in different languages for individuals who speak English as a second language. Services are offered for free or a small fee. For more information or to find an LITC near you, see the LITC page on the TAS website or Publication 4134, Low Income Taxpayer Clinic List.

Where am I in the tax system?

IRS Issues Math Error Notice

Balance Due Notice CP11