Notice Type
A CP12 notice means the IRS corrected an error on your tax return, and the correction changed your refund amount from what you originally claimed — this can mean a different refund than expected, or a refund where you originally expected to owe. The notice explains what was changed and the new amount, and this type of notice often fits well within our standard $45 notice review, since it usually just requires understanding what changed and confirming whether the IRS's correction is accurate.
Before You Respond
A CP12 means the IRS has already recalculated your return and adjusted your refund, so it's worth a close look even though it can seem like routine good news. Check the date printed on your actual notice — CP12 notices generally include a window during which you can contact the IRS if you disagree with the correction, and that date is what determines your timeline, not a general rule of thumb. If no response is made by that date, the IRS's adjusted figures are treated as final. Reviewing the notice before that date keeps you able to raise questions if the new amount doesn't match your own calculations.
Know Before You Act
Before assuming the new refund amount is automatically correct, it helps to understand two things: what specifically the IRS changed on your return, and whether that change matches your own calculations and records. The IRS may be correct. But the correction is sometimes based on incomplete information, and there can be a missing form, a credit or deduction that wasn't accounted for, a reporting mismatch, or a simple math difference behind the change. Knowing which of these applies to your situation is what determines whether the new amount is something to accept or something worth looking into further.
Start with a secure notice upload and a free IRS notice summary. If you want organized next steps, optional $45 Review & Guidance is a one-time purchase with no subscription. It may include an Action Plan, records to gather, response options, and case questions. When the information and supporting documents provided support a written IRS response, you can use the action steps provided to prepare it yourself or unlock the option for Think Twice Tax to draft a personalized response letter for you.