CP12: Math Error, Overpayment Refund
The IRS found a calculation error in your favor — you're getting a larger refund than you claimed.
Deadline
No hard deadline
Do I owe money?
No, they owe you
What does CP12 mean?
CP12 is good news. The IRS corrected a math error on your return that resulted in an overpayment. You will receive a refund larger than you originally expected, or your balance due was reduced to zero. Review the notice to confirm you agree with the change before depositing any refund check.
What should you do next?
- 1Read the notice to understand what was changed and verify the corrected refund amount
- 2If you agree: no action needed — the refund will be issued automatically
- 3If you disagree: call the number on the notice within 60 days
- 4Update your records to reflect the corrected tax liability for this year
Frequently asked questions
How long until I get my CP12 refund?
After CP12 is issued, refunds typically arrive within 4-6 weeks by check or direct deposit. You can track the status at IRS.gov/Refunds using 'Where's My Refund?'
Do I need to do anything to receive my CP12 refund?
No action is required if you agree with the correction. The IRS will automatically issue the refund. If you disagree with the change, call the number on the notice within 60 days.
Not sure what your notice means?
Paste your full notice text into the IRS Notice Explainer and get an instant plain-English explanation with a deadline and action steps — free, no account required.
Explain my noticeLast updated: 2026-05-18