How long do I have to respond to IRS CP106?

Write to the IRS within 60 days if you disagree. Use the deadline printed on your notice and verify how it is calculated. IRS deadlines may run from the notice or mailing date and are not automatically extended because the letter arrived or was opened late.

What should I do if I received IRS CP106?

Compare the notice with your return, then pay or arrange payment by the due date, or write to the IRS within 60 days if you disagree. If you are unsure, have a tax professional review the letter before you respond to the IRS.

IRS CP106 Notice: Return Miscalculation Created a Balance Due

The IRS believes your return has miscalculations and the changes created a balance due. Pay by the due date, or write to the IRS within 60 days if you disagree.

Published by the Law Offices of Darrin T. Mish, P.A.Updated October 13, 2026

Notice: CP106
Urgency: Urgent
Deadline: Write to the IRS within 60 days if you disagree

Your first move

Compare the notice with your return, then pay or arrange payment by the due date, or write to the IRS within 60 days if you disagree.

A CP106 notice means the IRS believes your return has miscalculations. The changes it made resulted in a balance due.

What to Do

Compare the figures on your return with the figures on the notice.
If you agree, make the changes to your copy of the return for your records.
Pay the total amount due shown on the notice, or call the IRS before the payment due date to make payment arrangements.
If you pay by mail, allow enough time for it to arrive. A late payment means additional penalties and interest.

If You Disagree

Contact the IRS in writing within 60 days. The IRS will review your information and reverse the changes if you can show it made a mistake.

Back your position with documents. Show the correct computation and the records that support each figure in question.

If you don't have documentation to justify a reversal, the IRS will forward the case for audit. The auditor will contact you within 5 to 6 weeks to explain the process.

If You Can't Pay in Full

Pay as much as you can now. Then call the number on the notice to discuss payment options. Paying part of the balance now reduces the interest and penalties that keep building on the rest.

Protect Yourself

Keep a copy of the notice and everything you send.
Send written disputes by certified mail so you can prove the date.
If someone else is handling this for you, authorize them with Form 2848 so the IRS can talk to them.

Questions about the notice go to the IRS number at the top of the notice.

If you received a CP106 notice and want help disputing or paying it, call us at (813) 229-7100.

This letter has a clock on it. Don’t run it out alone.

Free consultation with Darrin T. Mish, a Tampa tax attorney licensed since 1993 and admitted to the U.S. Tax Court. Bring the letter.

Call (813) 229-7100

Request a consultation online