How long do I have to respond to IRS CP128?

Pay by the date on the notice. Check the date and any response deadline printed on your notice, and follow the notice's instructions.

What should I do if I received IRS CP128?

Check the payments the IRS applied, then pay the remaining balance by the date on the notice or set up a payment plan. If you are unsure, have a tax professional review the letter before you respond to the IRS.

IRS CP128 Notice: Balance Still Due After Overpayment Applied

The IRS applied an overpayment from another period to your account, but a balance remains. Pay the remaining amount by the date on the notice.

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

Notice: CP128
Urgency: Urgent
Deadline: Pay by the date on the notice

Your first move

Check the payments the IRS applied, then pay the remaining balance by the date on the notice or set up a payment plan.

What This Notice Means

The IRS took an overpayment from another tax form or tax period on your taxpayer identification number and applied it to this account. That is called an offset-in. The overpayment didn't cover everything. You still have a balance due on the tax period shown on the notice.

The notice lists the date and amount of each payment the IRS applied. It may also suggest additional steps depending on your situation.

What to Do

Review the notice and the payments listed.
If you owe, pay the amount due now.
If you're enrolled in EFTPS, the Electronic Federal Tax Payment System, you can pay that way.
If you pay by check or money order, make it payable to the United States Treasury. Write your employer identification number (EIN), the tax form number, and the tax period on it. Use the envelope that came with your notice, or send it to the address in the upper left-hand corner of the notice.
Keep a copy of the notice for your records.

If You Disagree

If the IRS misapplied a payment or didn't credit one you made, call the number on your notice. Have your documentation ready, such as cancelled checks or an amended return. Tell the representative you received a CP128 and need to review your account. Have the notice and your return with you.

If You Can't Pay

See if you qualify for a payment plan through the IRS Online Payment Agreement application. Interest accrues on any unpaid balance after the date on the notice, and you'll be charged a late payment penalty if you don't pay in full.

If you can't pay because of circumstances beyond your control, contact the IRS by the payment due date. Depending on your situation, the IRS may be able to remove the penalty.

If you've tried several times to get answers from the IRS without success, the Taxpayer Advocate Service may be able to help.

Next Year

Claim the proper amount of credit on your next return. You may need to adjust your estimated tax payments or federal tax deposits.

If you received a CP128 notice and can't pay the remaining balance, 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