What the IRS says: “The income or payment information the IRS has on file doesn't match what you reported, and the IRS is proposing changes to your tax return.” Here’s what it actually means, your deadline, and exactly how to respond.
A CP2000 is not a bill and not an audit — it's a computer-generated proposal. The IRS matched your return against W-2s, 1099s and other third-party forms, found a difference, and recalculated your tax with penalties and interest. The proposed amount is frequently wrong: it ignores cost basis on stock sales, misses deductions tied to the income, and double-counts amounts already reported elsewhere on your return. You choose to agree, partially agree, or dispute — in writing, by the response date.
Notice family: Underreporter & Audit — The IRS thinks your return doesn't match its records — or wants to examine it. These notices carry hard response deadlines, and a written response with documentation is exactly how they get resolved.
30 days — from the date printed on the notice — the response date is on page 1.
Counted in calendar days from the notice date. The exact respond-by date printed on your notice always controls — check page 1.
Compare the notice's line-by-line list against your return and your own 1099/W-2 copies before anything else
If the IRS is right: sign the response form, arrange payment — and check whether a state amendment is needed too
If partially right or wrong: respond in writing with a corrected calculation and documents (broker statements showing basis, 1099 corrections)
Never file a 1040-X for the CP2000 items themselves — respond to the notice unit instead, and by the deadline
Respond in writing even to say you disagree — a clear letter that walks through each proposed item, states agree/disagree per item, shows the math, and lists the attached proof is exactly what the AUR unit needs to close the case in your favor. If the response window is closing, a letter requesting more time protects you.
Describe the notice and your side of it — use placeholders, never your SSN or account numbers (the letter keeps [YOUR NAME]-style fields so you fill in the real details privately before mailing). A mail-ready draft with an enclosure checklist comes back in ~20 seconds.
Your IRS response letter draft will appear here.
The income or payment information the IRS has on file doesn't match what you reported, and the IRS is proposing changes to your tax return. In practice: A CP2000 is not a bill and not an audit — it's a computer-generated proposal. The IRS matched your return against W-2s, 1099s and other third-party forms, found a difference, and recalculated your tax with penalties and interest. The proposed amount is frequently wrong: it ignores cost basis on stock sales, misses deductions tied to the income, and double-counts amounts already reported elsewhere on your return. You choose to agree, partially agree, or dispute — in writing, by the response date.
You generally have 30 days — from the date printed on the notice — the response date is on page 1. The respond-by date printed on your own notice always controls.
Respond in writing even to say you disagree — a clear letter that walks through each proposed item, states agree/disagree per item, shows the math, and lists the attached proof is exactly what the AUR unit needs to close the case in your favor. If the response window is closing, a letter requesting more time protects you.