CP13

A CP13 says the IRS corrected a mistake on your return, and after the correction you owe nothing and are owed nothing — the account sits at zero. It exists mostly to tell you the return you filed isn't quite the return on file anymore.

“We changed your return; the result is a zero balance — no refund, no bill. If you agree, no response is needed; just correct your own copy. If you disagree, contact us by the date on the notice.”

The same preserved-rights rule applies here as on the CP11 and CP12: disagreeing by the printed date keeps formal reversal and Tax Court appeal rights intact. And a zeroed refund you were counting on is a legitimate reason to disagree.

• The notice's 'What we changed' section
• Your copy of the return, especially if it claimed a refund the correction erased
• The document supporting the original figure
• Nothing, if the zero looks right

• Checking whether the 'correction' silently removed a credit or payment you were entitled to
• Requesting reversal with support inside the window
• Confirming the account really is settled, via transcript
• Fixing the underlying cause so next year's return doesn't repeat it