IRS NOTICE CP12
Math Error — Refund Adjusted
Quick answer
The IRS corrected a math or clerical error on your return, and your refund changed as a result.
What is an IRS CP12 notice?
The IRS corrected a math or clerical error on your return, and your refund changed as a result.
A CP12 is a correction the IRS already made to a return. It is not an audit and not a notice of deficiency. For the IRS's own overview of notices and letters, see the official Understanding Your IRS Notice or Letter page on IRS.gov.
What does a CP12 look like?
A genuine CP12 is a paper notice with the notice number "CP12" printed in the upper-right corner, the tax year it concerns, a short plain summary of the issue, the amount involved (if any), and a section explaining how and by when to respond.
When reading a CP12, it helps to locate four things: the notice code (so you know which notice it is), the tax year it applies to, any dollar amount, and the response or payment date. Those four details tell you most of what the notice is about.
Why did the IRS send a CP12?
Calculation discrepancy, missing schedule, or mis-applied credit found during processing.
Is a CP12 real, or a scam?
Scam letters sometimes imitate IRS notices. A real CP12 arrives by mail, shows an official notice number, and never demands payment by gift card, wire, or cryptocurrency, and never threatens immediate arrest.
- • The IRS generally makes first contact about a notice by mail, not unsolicited email, text, or a phone call.
- • Real notices reference a specific tax year and a notice number like CP12.
- • The IRS does not demand gift cards, wire transfers, or crypto, and does not threaten immediate arrest or deportation.
- • When unsure, verify by calling the IRS directly at 1-800-829-1040 or the number listed on IRS.gov.
How time-sensitive is a CP12?
A CP12 generally carries a firm, time-sensitive deadline. Always confirm the exact date printed on your own letter and go by that date. Because of what is involved, this is one many people review with a licensed tax professional.
What happens if you don't respond to a CP12?
Ignoring an IRS notice generally makes the situation harder to resolve — interest and penalties can continue to build, and the IRS can send further notices or take further action. It is almost always better to review the notice and respond by the printed date.
General next steps
In general, these are some of the steps people take for this type of notice — not advice about your specific situation.
- Read the CP12 in full and note the notice code (top-right corner), the tax year, and any date it lists.
- Compare the amounts and any change shown on the notice against your filed return and your own records.
- Respond only in the way the notice itself describes, and by the date printed on it.
- If you are unsure whether the notice is correct or how to respond, contact the IRS at the phone number printed on it, or a licensed tax professional — a CPA, an Enrolled Agent, or a tax attorney.
When to get help
Many notices can be reviewed and handled by reading them carefully. For serious or confusing ones, or if you are unsure, contact the IRS at the number printed on the notice, or a licensed tax professional — a CPA, an Enrolled Agent, or a tax attorney.
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Frequently asked questions about the CP12
What is an IRS CP12 notice?
The IRS corrected a math or clerical error on your return, and your refund changed as a result.
Why did I receive a CP12?
Calculation discrepancy, missing schedule, or mis-applied credit found during processing.
What does a CP12 look like?
A genuine CP12 is a paper notice from the IRS with the notice number "CP12" printed in the upper-right corner, the tax year it concerns, a short summary of the issue, and a section explaining how and by when to respond.
How time-sensitive is a CP12?
A CP12 generally carries a firm, time-sensitive deadline. Always confirm the exact date printed on your own letter and go by that date. Because of what is involved, this is one many people review with a licensed tax professional.
Is a CP12 a scam?
Some scam letters imitate IRS notices. A real CP12 arrives by mail, shows an official notice number, and never demands payment by gift card, wire transfer, or cryptocurrency, and never threatens immediate arrest. When in doubt, verify by calling the IRS at 1-800-829-1040.
What happens if I ignore a CP12?
Ignoring an IRS notice generally makes things harder to resolve — interest and penalties can continue to build and the IRS can send further notices or take further action. It is almost always better to review it and respond by the printed date.
Do I need a tax professional for a CP12?
Many notices can be reviewed and handled by reading them carefully and responding as instructed. For serious or confusing notices, or if you are unsure, a CPA, Enrolled Agent, or tax attorney can help. This is educational information, not advice about your situation.
How do I know a CP12 is really from the IRS?
The IRS initiates contact about a notice by mail, not by unsolicited email, text, or phone. A real CP12 has an official notice number and references a specific tax year. You can confirm any notice by calling the IRS directly using the number on IRS.gov.
Tax Panic provides educational information only. This is not tax or legal advice, does not interpret your legal rights, and does not tell you what to do about your specific situation. Not affiliated with the IRS. For your situation, contact the IRS at the number on your notice or a licensed tax professional.