Letter 525
act on thisGeneral 30-Day Letter (and Letter 915, Examination Report Transmittal)
The examination is over, here is what the IRS proposes to change, and you have 30 days to protest before it becomes formal.
Letter 915 transmits the examination report itself and carries the same 30 days. Related letters differ: Letter 692 gives 15 days, and Letter 1153 on the trust fund recovery penalty gives 60.
If it passes. A Notice of Deficiency — Letter 531 or CP3219A — and the hard 90-day Tax Court clock.
Why you got it
An examination produced proposed adjustments, sent with a computation report.
What rights it carries
Protest to the Independent Office of Appeals. Not a deficiency notice, so no Tax Court right yet.
Do you have to respond?
Optional. The consequence of silence is the deficiency notice.
The mistake people make
Letting the 30 days run in order to 'go to Tax Court instead'. Appeals is faster and cheaper and has settlement authority that Tax Court counsel does not exercise until much later. Skipping it preserves nothing you did not already have; it only costs you a forum.
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
CP2000 — The IRS thinks third parties reported income you did not report, and it is proposing — not assessing — more tax. 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. CP12 — The IRS corrected your return and you are owed a refund, or your refund amount changed.Every notice in the library → Not sure it is really from the IRS? →
Sources: IRS Appeals — letters and notices offering an appeal opportunity. 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.