CP12
informationalOverpaid Math Error — Refund Due
The IRS corrected your return and you are owed a refund, or your refund amount changed.
The IRS page prints the date rather than the count; the 60 days comes from IRC § 6213(b)(2), the same provision as the CP11.
If it passes. Same as the CP11: you lose the formal right to have the change reversed and the right to appeal it to Tax Court.
Why you got it
A math or clerical error correction that went your way.
What rights it carries
The § 6213(b)(2) abatement request. No Tax Court right off the notice.
Do you have to respond?
Optional if you agree — the refund arrives in four to six weeks.
The mistake people make
Cashing the changed refund without reading the adjustment. A CP12 that hands you money often reflects the IRS disallowing something — a credit, a loss, a basis figure — and the same correction will follow you into later years.
If crypto is why this arrived, the number on it is probably wrong.
Your exchange reports what you sold for and leaves the cost box blank, so any figure the IRS computes from it treats every coin as though it cost you nothing. Rebuild the basis from your own transaction history — free — and see the real number before the deadline above runs out.
Notices that arrive around this one
CP3219A — The formal determination that you owe more tax — the ninety-day letter, and your one ticket to Tax Court without paying first. CP11 — The IRS corrected something on your return and now says you owe money. CP23 — You claimed more in estimated tax payments than the IRS has on record, and now you owe. CP14 — Your first bill. Tax has been assessed and it has not been paid.Every notice in the library → Not sure it is really from the IRS? →
Sources: IRS — Understanding your CP12 notice. Retrieved 2026-08-28. Where the IRS publishes no day count we say so rather than repeat a number we cannot source — the date printed on your own notice is the one that governs. ClearBasis is tax software, not a tax adviser, and this is information rather than advice.