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 CP161 Notice


You received this notice because you have an unpaid balance due.

What you need to do

  • Read your notice carefully ― it explains how we calculated the amount due.
  • Compare the figures on the notice with your tax return.
  • Check the list of payments we applied to your account to see if we applied all the payments you made.
  • Contact us within 10 days of the date of your notice if you think we made a mistake.
  • Pay the amount due by the date on the notice.
  • Contact us to make payment arrangements if you can't pay the full amount you owe. You can also read more about payment options here.

You may want to

Answers to Common Questions

  • Will you charge me additional interest on the amount I owe?
    We don’t charge additional interest if you pay the full amount you owe by the payment due date. However, interest will continue to increase on the unpaid balance after the payment due date.

  • Will I receive a penalty if I can't pay the full amount?
    Yes. You will receive a late payment or failure to deposit penalty, depending on what you owe. Notice 746, Information About Your Notice, Penalty and Interest, has more information about penalties and interest.

  • What happens if I can't pay the full amount I owe?
    You can request a payment plan if you can't pay the full amount you owe. Call us at the toll-free number on your notice to discuss payment options or learn more about them here.

  • What should I do if I disagree with the notice?
    Contact us at the toll-free number on your notice. Please have your documentation (such as cancelled checks, amended return, etc.) ready when you call.