Understanding your CP23 notice

What this notice is about

We changed your return because we found a difference between the amount of estimated tax payments on your tax return and the amount we posted to your account. You have a balance due because of these changes. The notice may also cover other changes we made while processing your return.

What you need to do

  • Read your notice carefully. It will explain how much money you owe on your taxes.
    • Compare the payments on the notice to your records:
      • Verify we listed all your estimated tax payments.
      • Check the payments we applied (if any) from the prior year.
  • If you agree with the changes we made,
    • Pay the amount owed by the date on the notice.
    • You may do this online at Payments.
    • Establish a Payment Plan or Installment Agreement if you can't pay the full amount you owe.
    • You may do this using the Online Payment Agreement tool, or by contacting us at the  number on the notice.
    • Correct the copy of your tax return that you kept for your records. Don’t send your copy to us.
  • If you don’t agree, contact us within 60 days from the date of your notice and see “Answers to Common Questions” below.
    • By telephone: Call us at the toll-free number shown on your notice. Some cases require additional information that you may provide verbally. Either way we may be able to correct your account immediately.
    • By mail: Please include a copy of the notice along with your correspondence or documentation and allow 30-60 or more days for a resolution.

Frequently asked questions

The most common cause is an incorrect entry on the estimated tax line of the tax return. If this happened, call at the number on your notice.

Call us at the number on your notice. Have a copy of your tax return and documentation (such as cancelled checks or amended return) ready when you call. We'll discuss the issue with you and give you further instructions.

We may assess an estimated tax penalty if you didn’t pay enough tax throughout the year, either through withholding or by making estimated tax payments. See our Estimated taxes page, or Tax Topic 306, Penalty for underpayment of estimated tax.

Yes. You will usually receive a late payment penalty. If we adjust your account (such as fixing a misapplied payment), the late payment penalty and interest will adjust automatically. For additional help, see Penalty relief.

To avoid interest charges, pay the amount owed by the due date on the payment coupon. We can't reduce interest for reasonable cause or first-time relief. We're required by law to charge interest, and it will continue until your account is fully paid. However, if we reduce your tax or penalty, the interest will automatically be reduced.

Tips for next year

Consider filing your taxes electronically. Filing online can help you avoid mistakes and find credits and deductions that you may qualify for. In many cases you can file for free. Learn more about e-file.

To help avoid the same issue next year, correct the copy of this year’s tax return that you kept for your records. If you use a tax preparer, also have them correct their copy.

Before filing your return, you can verify the estimated tax payments applied to the year by viewing your tax account.

Helpful information

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