U.S. · IRS notices
IRS CP133 notice explained.
A notice that the IRS changed your return after a miscalculation and there is an overpayment on the account.
CP133 says the IRS changed your tax return because it believes there is a miscalculation, and as a result there is an overpayment on your account. If you disagree, the IRS page says to contact the IRS within 10 days from the date of the notice. If you owe no other taxes or debts the IRS must collect, it says you should receive the refund within four to six weeks.
Compare IRS CP notices
Result
CP notices at a glance
| Notice | What the IRS page says it is | Response, as the IRS page states it |
|---|---|---|
| CP2000 | The income or payment information the IRS received from third parties, such as employers or financial institutions, does not match what was reported on the tax return. | Reply to the notice by the date listed on it. The IRS says the notice is not a bill and a response may be required. |
| CP13 | The IRS corrected one or more mistakes on the return. The taxpayer is not due a refund and does not owe an additional amount because of the changes; the account balance is zero. | No response if you agree. If you disagree, contact the IRS at the number on the notice by the date indicated. |
| CP16 | The IRS corrected one or more mistakes on the return. Because the taxpayer or spouse owe other tax debts, the IRS applied all or part of the refund to pay off those debts. | No response if you agree. If you disagree, contact the IRS at the number on the notice by the date indicated. |
| CP103 | The IRS made changes to the return because it found a miscalculation, and the balance due changed as a result. | Contact the IRS within 60 days of the date of the notice if you disagree. Pay by the date on the payment coupon. |
| CP107 | The IRS made changes to the return because it found a miscalculation, and the balance due changed as a result. | Contact the IRS within 60 days of the date of the notice if you disagree. Pay by the payment due date on the notice. |
| CP108 | The IRS received a payment but could not determine the correct form or tax year to apply it to. | No response if the payment was applied correctly. If not, tell the IRS where to apply it, by phone or Form 15108. |
| CP133 | The IRS made changes to the return because it believes there is a miscalculation, and as a result there is an overpayment on the account. | Contact the IRS within 10 days of the date of the notice if you disagree, by phone or by mailing the completed contact stub. |
| CP136 | The employer’s deposit requirement for Form 941 filings next year may differ from last year’s, based on the total tax reported on the Forms 941 for the four previous consecutive quarterly periods (the lookback period). | The IRS page prints no response date. It says to check your records against the notice and, if a Form 941 is missing, to file it as soon as possible. |
| CP152 (IRS page) | The IRS received the tax-exempt bond form. | No action needed; keep the notice for your records. |
| CP153 | The IRS cannot provide the refund through direct deposit and is sending the refund or credit payment by mail. | No response is requested. Expect the refund within 3-4 weeks of the notice date; contact the IRS if it has not arrived after 4 weeks. |
| CP2005 | The IRS accepted the information sent, will not change the return, and has closed its review. | No response is required. |
The notice number is printed on the notice itself, usually in the top right corner. Use the number exactly as printed; the table follows the IRS page for each number.
What the IRS says the notice is
“We made changes to your tax return because we believe there’s a miscalculation on your return. As a result of these changes, there’s an overpayment on your account.” The notice explains the changes made.
What the IRS page asks you to do
Read the notice, compare its figures with your tax return, and if you agree correct your copy of the return. If you don’t agree, contact the IRS within 10 days from the date of the notice by calling the toll-free number on it or by mailing the completed contact stub with any correspondence or documentation.
The refund
The page says that, if you haven’t already, you should receive a refund of the overpayment within four to six weeks if you owe no other taxes or debts the IRS is required to collect, and you don’t need to take further action. The FAQ adds the condition that the refund amount is $1 or more, and says that if six weeks pass without a refund and you owe nothing else, to call the toll-free number on your notice.
Why the return changed
The IRS page does not list reasons in general; the FAQ says to call the toll-free number on the notice for specific information about your return.
Forms and publications
The page tells you to see Forms, instructions & publications or call 800-TAX-FORM (800-829-3676) for forms. Helpful-information links include Publication 505, Publication 542 (Corporations), Publication 559 and Publication 598 (Tax on Unrelated Business Income of Exempt Organizations).
How this page differs from the others
The 10-day window is much shorter than the 60 days printed for CP103 and CP107.
More IRS notice pages
Other pages in this set: CP2000, CP13, CP16, CP103, CP107, CP108, CP136, CP153, CP2005. For the codes on an IRS account transcript, see the IRS transcript codes lookup. For how interest and penalties are worked out on a balance, see the IRS penalty and interest calculator.
Sources
- Understanding your CP133 notice: what the notice is, the 10 days, refund FAQ. Read November 2, 2026.
IRS page last reviewed July 21, 2026. This page restates what the IRS page says and adds nothing beyond it: no timelines, outcomes or advice that the IRS page does not state. The IRS can change a notice page at any time; the notice you received controls, including its response date and contact details.
Frequently asked questions
What does an IRS CP133 notice mean?
The IRS made changes to your tax return because it believes there is a miscalculation, and as a result there is an overpayment on your account.
How long do I have to disagree with a CP133?
The IRS page says to contact the IRS within 10 days from the date of the notice if you do not agree with the changes.
How do I contact the IRS about a CP133?
By calling the toll-free number on the notice or by mailing the completed contact stub with any correspondence or documentation.
When will the CP133 refund arrive?
The IRS page says within four to six weeks if you owe no other taxes or debts the IRS is required to collect.
Will I get a refund of any size after a CP133?
The FAQ says yes, provided you owe no other outstanding liabilities the IRS must collect and the refund is $1 or more.
Not tax or legal advice
This page summarizes IRS notice pages and is not tax, legal or financial advice. It does not tell you how to respond to a notice beyond what the IRS page states. The notice you received controls. A CPA, enrolled agent or tax attorney, or the IRS number printed on your notice, can confirm what applies to you. Everything runs in your browser; nothing you enter is sent anywhere.