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The IRS changed your return

IRS CP12

The IRS corrected your return and changed your refund

Respond by

If you disagree, contact the IRS at the number on the notice by the date indicated

Who sent it

IRS
Facts on this page come from that IRS page, last updated by the IRS Aug 11, 2026; read by TaxScout Oct 19, 2026.

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What this letter asks of you, what to gather, and what to ask a professional if you need one. No phone number asked.

What this letter means

The IRS corrected one or more mistakes on your tax return, and as a result you are now owed a refund or your original refund amount has changed.

A correction the IRS made while processing, which changed your refund or balance.

What to do

  1. 1Read the notice carefully to see what changed and how it affected your refund.
  2. 2If you agree, no response is required; expect a refund check in about 4–6 weeks unless you owe other tax or debts.
  3. 3Correct your own copy of the return for your records, but do not send it to the IRS.
  4. 4If you disagree, contact the IRS at the toll-free number in the 'Where to find more information' section of your notice by the date indicated.
  5. 5You can use your IRS Online Account to view your balance, payments and transcripts.

The IRS page describes two paths, one if you agree with the change and one if you do not. The response form that came with your letter is where you mark which one applies.

If you do nothing

If you do not contact the IRS by the deadline you lose formal rights to have the changes reversed and your right to appeal to the U.S. Tax Court, though late documentation will still be considered.

Is this letter real?

IRS letters arrive by mail and carry a notice number, your name and the tax year. The IRS does not open contact by text, email or social media, and does not ask for payment by gift card.

Check the notice number against the official IRS site before you respond, and respond only to the address or number printed on the official page.

Common questions

What is IRS CP12?

The IRS corrected one or more mistakes on your tax return, and as a result you are now owed a refund or your original refund amount has changed. The IRS page for it is titled 'Understanding your CP12 notice (including CP12, CP12E, CP12F, CP12G, CP12N, and CP12U)'.

How long do I have to respond to CP12?

If you disagree, contact the IRS at the number on the notice by the date indicated. The date printed on your letter controls; the IRS page for this notice is the source.

What happens if I ignore CP12?

If you do not contact the IRS by the deadline you lose formal rights to have the changes reversed and your right to appeal to the U.S. Tax Court, though late documentation will still be considered.

Is CP12 a scam?

IRS notices arrive by mail with your name, a notice number and a tax year. Check the number on the official site before you respond, and never pay by gift card or wire on the strength of a phone call.

Do I need a CPA for CP12?

Not always. Upload the letter and the free report explains what it asks for and what to gather; if a professional makes sense, the report says why and what to ask. TaxScout never shares your request with any firm unless you ask for that on the report.

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Not tax advice. TaxScout is not the IRS. Deadlines and steps above are quoted from the IRS page linked at the top and may change; the letter in your hand controls.