Information For...

For you and your family
Standard mileage and other information

Forms and Instructions

Individual Tax Return
Instructions for Form 1040
Request for Taxpayer Identification Number (TIN) and Certification
Request for Transcript of Tax Return


Employee's Withholding Allowance Certificate
Employer's Quarterly Federal Tax Return
Employers engaged in a trade or business who pay compensation
Installment Agreement Request

Popular For Tax Pros

Amend/Fix Return
Apply for Power of Attorney
Apply for an ITIN
Rules Governing Practice before IRS

Understanding your CP45 Notice

We were unable to apply your overpayment to your estimated tax as you requested.

What you need to do

  • Read your notice carefully - it will explain why we were unable to apply the amount you requested to the following year’s taxes. It may also suggest additional steps for you to take, depending on your situation.
  • Correct your copy of your tax return for your records.
  • Adjust this year’s estimate tax payments to avoid any possible underpayment.

You may want to

Answers to common questions

How do I adjust my estimated tax payments?
You can adjust your estimated tax payments by completing Form 1040-ES, Estimated Tax for Individuals. For more information, see Publication 505, Tax Withholding and Estimated Tax.

What is an "overpayment," and how is that different from a "refund?"
An "overpayment" occurs when you pay more taxes during the year, either through withholding on wages or by making estimated payments, than what you owe. This can either be refunded to you or applied to your next year's taxes.

How can I find out what happened on my tax return this year that would cause this change?
Please contact us at the number listed on your notice for the specific information concerning your tax return.

Will the IRS send me another notice to confirm the overpayment has been applied?
No, this notice is your notification of the amount we’re applying to your account.

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.