CP2501
read it properlyCP2501 notice
An earlier, softer version of the CP2000: the IRS has spotted a mismatch but has not yet computed a proposed tax change.
The IRS publishes no day count for this notice — its own page and Publication 5181 both say only 'by the deadline given in the notice'. The 30 days you will read elsewhere is not sourced. The date printed on your copy is the one that governs.
If it passes. The case advances to a CP2000 with a computed deficiency, and from there to a notice of deficiency.
Why you got it
The same third-party mismatch that produces a CP2000, caught one stage earlier.
What rights it carries
Appeal through the Independent Office of Appeals. No Tax Court right — this is not a deficiency notice.
Do you have to respond?
Required. The notice says it is not a bill, and that you must respond.
The mistake people make
Treating it as junk mail. This is the cheapest off-ramp there is: you can supply the missing cost basis before the IRS computes a number at all, before penalties are proposed, and before any deficiency clock exists.
If your exchange filed a 1099-DA with proceeds and no basis, this is where you close the gap for the price of a letter.
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
Letter 6173 — A compliance demand about crypto. Unlike its two siblings, this one requires an answer by a printed date. Letter 6174 — An educational letter. The IRS knows you have or had virtual currency accounts and wants you to know the rules. CP2000 — The IRS thinks third parties reported income you did not report, and it is proposing — not assessing — more tax. Letter 525 — The examination is over, here is what the IRS proposes to change, and you have 30 days to protest before it becomes formal.Every notice in the library → Not sure it is really from the IRS? →
Sources: IRS — Understanding your CP2501 notice · IRS Publication 5181. 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.