IRS notice
IRS Notice CP12: Why Your Refund Is Different
The IRS corrected your return and changed your refund, or created one. Agree and do nothing, or dispute within 60 days.
Reply by the date on the notice
The date on the notice, 60 days from the notice under IRC 6213(b)(2), is the last day to dispute the correction and keep your formal right to have it reversed.
This deadline is set by law and cannot be extended.
A CP12 means the IRS corrected one or more mistakes on your return and, as a result, your refund is different from what you expected, or you are getting a refund when you expected to owe or break even. If you agree, you don't need to reply. If you disagree, contact the IRS within 60 days of the notice, by the date shown, to have the correction reversed.
What this notice is telling you
- The IRS made a math error correction to your return without an audit.
- The correction changed your refund amount, or turned an expected balance due or zero balance into a refund.
- If you agree, the IRS says a refund check should arrive in 4 to 6 weeks, provided you don't owe other taxes or debts it must collect.
What to do
Find what changed
The "What we changed on your return" section lists each correction. Check it against the return you filed and the forms behind it.
Look for a credit that was reduced
Refund changes often trace to a refundable credit the IRS recalculated or a figure it couldn't match. Note the line involved before you call.
If you agree, do nothing
No reply is needed. Update your personal copy of the return for your records, but don't send it to the IRS.
If you disagree, call by the date on the notice
Use the toll-free number in the notice's information section. The IRS says the phone is the fastest route, and you may be able to fax missing documents during the call.
Be ready for an examination letter
If the IRS doesn't receive support for your original figures, it may refer the return to audit, and audit staff would contact you within about six weeks.
When a CP12 is good news, and when to push back
A CP12 can go either way. Sometimes the IRS spots a credit or a calculation in your favor and the refund goes up, or a return that showed a small balance due turns into a refund. In that case, check that the correction is right and keep the notice with your return. When the refund goes down, it is worth checking closely: math error corrections are made from what the IRS can see on the return and in its records, so a missing schedule or a figure the IRS couldn't match can reduce a refund even when you were entitled to the amount you claimed.
| You | Result |
|---|---|
| Agree (no reply) | The corrected refund is issued, generally in 4 to 6 weeks if no other debts apply |
| Dispute within 60 days | The IRS generally reverses changes that reduced your refund; it may refer the return to audit if support is missing |
| Dispute after 60 days | The IRS considers documents you send and may reverse the change if it agrees, but your formal rights are gone |
Why the deadline carries weight
Because a CP12 is a math error notice, it isn't a notice of deficiency and doesn't by itself give you a Tax Court petition. The 60-day request is what protects you: a timely request means the IRS has to reverse the correction and, if it still disagrees, go through the regular examination and deficiency process to change your tax. Under a 2025 law (Pub. L. 119-39), math error notices sent starting late November 2026 must also state the exact date of that 60-day deadline and explain the error and the line involved.
Want a CPA to deal with it?
Bring the notice to a free consultation, in person on James Island or by video. We read it with you, tell you what it means for your account and, if you want us to, take over the response once you sign Form 2848.
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Sources
By Haigler CPA Group. Updated . Notices are revised from time to time, so go by the wording and dates on your own notice. The information on this site is general in nature and is not tax, legal, or accounting advice for your situation. Tax law changes and the right answer depends on facts we would need to review with you. Please speak with a qualified professional before acting on anything you read here.
Questions about CP12
Do I need to respond to a CP12 if I agree?
No. If you agree with the changes, no response is needed. The corrected refund should follow, generally within 4 to 6 weeks, unless other taxes or debts reduce it.
Can a CP12 mean a bigger refund?
Yes. The IRS sends a CP12 whenever a correction changes your refund, which can be up or down, or when a correction turns an expected balance due or zero balance into a refund.
Do I have to send documents to dispute a CP12?
Not if you contact the IRS by the deadline. The IRS will generally reverse the changes that reduced your refund, though documents can speed things up and help avoid an audit referral.
Where can I read about my appeal rights for a CP12?
The IRS points to Publication 5 for appeal rights and Publication 3598 for audit reconsideration.
Other notices
- CP11: We corrected your return and you oweThe IRS corrected what it sees as a math or similar error, leaving a balance due. You have 60 days to dispute and have it reversed.
- CP05: The IRS is reviewing your return before releasing your refundThe IRS needs more time to verify income, withholding, credits or business income on your return; if you filed it, no reply is needed.
- IRS notice lookupEvery IRS notice carries a code. Find yours below to see what it generally means, which date matters, and what to do before that date passes.
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