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Key takeaways
- The notice or letter number is in the top or bottom right corner — it tells you what kind of letter it is.
- A CP2000 is a proposal, not a bill. You can agree, partially agree or disagree.
- Collection letters escalate on a schedule. The final notice of intent to levy starts a 30-day clock for important appeal rights.
- Never ignore a letter. Most of the damage comes from missed deadlines, not the original issue.
The IRS sends millions of letters every year. Most are routine: a math correction, a request to verify your identity, a reminder of a balance. Some are more serious. The notice number tells you which one you're holding, and the response date tells you how much time you have.
First: confirm it's real
The IRS begins contact by mail. It doesn't open a case by email, text message or social media, doesn't demand immediate payment over the phone, and never asks for payment by gift card or cryptocurrency. To check a letter:
- Log in to your IRS online account and see whether the notice or balance appears there.
- Look up the notice number on IRS.gov — each has an explanation page.
- Call the IRS using a number from IRS.gov, not one printed in a message you're unsure about.
Common notices and what they mean
| Notice | What it means | Typical next step |
|---|---|---|
| CP11 / CP12 | The IRS corrected a math or processing error, changing your balance or refund | Review; respond within 60 days if you disagree |
| CP14 | You have a balance due | Pay, or set up a payment plan |
| CP2000 | Income or payments reported to the IRS don't match your return | Respond by the date shown — agree or explain |
| 5071C / 4883C | The IRS needs to verify your identity before processing a return | Verify online or by phone as directed |
| CP501 / CP503 | Reminders of an unpaid balance | Pay or arrange a plan before it escalates |
| CP504 | Notice of intent to levy — including state tax refunds | Act now; call or get representation |
| LT11 / Letter 1058 | Final notice of intent to levy and your right to a hearing | Request a Collection Due Process hearing within 30 days if needed |
The CP2000, in detail
A CP2000 is generated when information the IRS received — from a W-2, 1099, 1099-K, brokerage statement or mortgage lender — doesn't match your return. The letter shows the specific items, the proposed additional tax, interest and often an accuracy penalty.
It's important to understand that a CP2000 is a proposal. You have three options:
- Agree — sign the response form and pay or set up a plan.
- Partially agree — accept some items and explain the rest.
- Disagree — explain why, with documents. Common reasons: the income was already reported elsewhere on the return, a 1099-K included personal transfers, the brokerage sale is missing its cost basis, or the form was issued in error.
Brokerage sales are the classic example. If a 1099-B didn't include your cost basis and you left the sale off your return, the IRS may treat the entire sale price as profit. Supplying the basis often reduces the proposed tax dramatically.
Respond by the date on the letter — usually about 30 days. If you need more time, ask for it before that date.
How collection notices escalate
If a balance goes unpaid, letters follow a predictable path: a balance-due notice, reminders, a notice of intent to levy, then a final notice that includes your right to a Collection Due Process hearing. Each step adds urgency and narrows your options.
The final notice matters most. Requesting a hearing within 30 days generally pauses levy action and gives you the right to propose alternatives, such as an installment agreement, and to take the case to Tax Court if needed. Our guide to back taxes and payment options covers those alternatives.
What to do today
- Open it. Unopened letters are the most expensive kind.
- Find the notice number, tax year and response date.
- Compare it to your return and records for that year.
- Don't pay a disputed amount just to make it go away — and don't ignore an amount you agree with.
- Send your response in a trackable way and keep copies.
In the ExcelTax Notice Center, you upload a photo of the letter and get a plain-English explanation, the deadline and our recommendation within one business day. If a response is needed, we write it.
This article is general information, current as of September 2026, and isn't tax advice for your situation. Figures are federal unless noted, and indexed amounts change each year — confirm current numbers with your tax pro before acting.