The first move
Read the proposal line by line before you agree to anything. Do not file an amended return; the notice process handles the change.
What these letters have in common
Every W-2, 1099, 1098, and K-1 you receive is also sent to the IRS. About a year after you file, the IRS matches them. A mismatch produces a CP2501 (a request for explanation) or a CP2000 (a proposed change with the tax computed). Businesses get CP2030 and letters in the 2531 series.
The mismatch is often real: a 1099 for a side job you forgot, interest from an account you closed. It is also often not what it looks like. Stock sale proceeds show up as pure income because the IRS cannot see your basis. A 1099 issued under the wrong year or duplicated by a payer shows up as unreported. Retirement rollovers show up as distributions.
Agreeing means signing the response and paying. Disagreeing means a short letter and documents for each item, sent by the date on the notice. Ignoring it means a statutory notice of deficiency and a 90-day Tax Court clock.
What to gather
- The notice, including the item-by-item list of what the IRS thinks is missing
- Your return for that year with all schedules
- Every 1099, W-2, 1098, and K-1 for that year
- Brokerage statements showing cost basis for any stock sales listed
- Rollover or conversion confirmations for any retirement distributions listed
- Proof of any item the IRS lists that was reported elsewhere on your return
How to write back
- CP2000 response letter: Explains a mismatch between what a third party reported and what you filed, agreeing in part or disagreeing with documents attached.
Notices in this family
| Notice | What it means |
|---|---|
| CP2000 | Proposed changes to your return based on income the IRS received from third parties |
| CP2005 | The IRS accepted your CP2000 response and closed the case with no change |
| CP2006 | The IRS received your CP2000 response and is reviewing it |
| CP2057 | You may need to amend a return; income reported to the IRS does not appear on it |
| CP2501 | Income on your return does not match what was reported; explanation requested before any tax is proposed |
| CP251 | Business return figures do not match information returns filed |
| CP253 | Business: W-2 totals reported to Social Security do not match Forms 941 |
| Letter 2030 | Business version of the CP2000 proposal |
| Letter 2531 | Business version of the CP2501 inquiry |
| Letter 6115C | Verification request tied to a return with mismatched information |
When to get help
If the proposed tax is more than you can pay, if it involves a property sale, or if you cannot reconcile the items, get help before you respond. The response date is not flexible without a call.
Before you send anything
This is general information, not tax advice. Situations differ. Check with your tax advisor before you send anything. Nothing on this page creates a client relationship.