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 CP51C Notice

We computed the tax on your Form 1040, 1040A or 1040EZ. You owe taxes.


What you need to do

  • Read your notice carefully. It will explain how we calculated your tax return.
  • You don't need to do anything if you agree with our calculations.
  • Contact us if you disagree with the amount of tax we computed.

Answers to Common Questions

What should I do if I disagree with the notice?
Call us at the toll free number on the top right corner of your notice. Please have your paperwork (such as cancelled checks, amended return, etc.) ready when you call.


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.

Printable samples of this notice (PDF)

How to get help