The short answer
A CP2000 is an IRS notice saying the income or payments reported to the IRS by employers, banks, or brokers do not match your tax return. It is not a bill and not an audit. It proposes changes. Read it, decide whether you agree, and reply by the date printed on the notice, with documents if you disagree.
Is this letter real?
Real CP2000 notices arrive by U.S. mail. The IRS says a letter or notice is the first way it contacts a taxpayer. It does not make first contact by email or social media, and it only texts people who signed up for its messages. It also will not ask for payment by gift card or prepaid card, and it does not leave urgent or threatening messages (IRS Tax Tip 2025-46).
To check that your CP2000 is genuine:
- Look in your IRS Online Account. Sign in at irs.gov/account (type the address yourself) and see whether the notice is in your file. The IRS lists this as a way to confirm a letter, though only certain notices appear there.
- Check the notice number. The IRS says the notice number (CP2000, or a variant like CP2000A) is in the right corner of the letter. Compare what your letter says with the IRS’s CP2000 explainer.
- If you are still unsure, call the IRS at 800-829-1040, a number published on IRS.gov, and ask them to confirm the notice. Do not rely on a phone number printed on a letter you suspect is fake.
Warning signs of a fake: a demand for payment by gift card or prepaid card; threats of arrest; or an email or text with a link asking you to “resolve” a CP2000. Don’t reply or click links. Send a suspicious IRS email to phishing@irs.gov with the subject “IRS”. For a suspicious text, email phishing@irs.gov with the subject “Text” and include the sender’s number and the message. You can also forward the text to 7726 (SPAM), which helps your wireless provider block similar messages (IRS reporting page).
What the letter says, section by section
The exact layout can vary, and there are several versions (CP2000, CP2000A, CP2000B, CP2000C, CP2000D, and CP2000E), but most include these parts:
- Notice number, tax year, and notice date. On the first page. The tax year tells you which return the IRS is looking at. The notice date matters because your reply deadline is tied to it.
- Response due date. The IRS asks you to “reply to the notice by the date listed.” Find that date on your notice. Do not guess it from what a friend received.
- Summary of proposed changes. The change to your tax the IRS proposes. It generally includes interest, and penalties may apply even if not shown (Topic 652).
- Income and payment information. A line-by-line comparison of what third parties (employers, banks, brokers, and others) reported versus what appeared on your return. Each mismatch is usually listed with the payer’s name. This is the heart of the notice.
- How the IRS calculated the change. How the mismatched amounts change your income, tax, credits, or payments.
- Response form. Many CP2000s include a form where you check whether you agree or disagree, sign, and send it back. It may also have an authorization section that lets someone else talk to the IRS about this notice for you.
- Where to reply. The IRS office that sent the notice is shown in the top left corner of the first page. The IRS fax number and mailing address you use depend on that location.
The Taxpayer Advocate Service puts it plainly: a CP2000 “is not an IRS audit or a bill.” It is a proposal: the IRS plans to adjust your return as listed unless you send information showing why your amounts are correct.
What to do next
- Find your reply-by date and put it somewhere you will see it. It is printed on the notice. The IRS suggests replying within 30 days of the notice date (60 days if you live outside the United States). If you need more time, the IRS says you can send an extension request with a reply option.
- Pull out your return for that year and every income form you received. Compare each item the IRS lists with your records (W-2s, 1099s, brokerage statements). Mismatches can come from things like a forgotten 1099 from a side job, a stock sale where the cost was not reported, or income that belongs to someone else.
- Decide which situation fits.
- You agree, and have nothing else to report: Follow the notice’s instructions and sign the response form (both spouses sign if you filed jointly). The IRS says you do not need to amend your return.
- You disagree, fully or partly: Complete and sign the response form, explain why, and include supporting documents. Send copies, not originals. If you fax, put your name and Social Security number or TIN on each page (TAS).
- The CP2000 is right, but you also have credits, expenses, or other income to report: The IRS says to complete Form 1040-X, write “CP2000” on top, and send it with your response form.
- A payer reported the wrong amount: You may need to ask that payer to issue a corrected form, and include what you have with your reply.
- Someone else used your identity to earn the income: The IRS says to send Form 14039, Identity Theft Affidavit, with your reply.
- Send your reply. The IRS lists three ways on its CP2000 page: upload through the IRS document upload tool (the page calls this the fastest way, and gives an access code for it), fax to the number for the IRS location shown in the top left of your notice, or mail to the address in the top left of the first page. Keep a copy of everything you send and when you sent it.
- If you agree and owe money, pay or set up a plan. You can pay at irs.gov/payments. The IRS notes that interest keeps accruing until the balance is paid and penalties may apply. Paying or setting up a plan does not replace the reply: you still return the signed response form by the due date. If you cannot pay in full, look at a payment plan. Individuals who owe less than $100,000 in combined tax, penalties, and interest can apply online for a short-term plan of up to 180 days, and those who owe $50,000 or less and have filed all required returns can apply for a long-term monthly plan.
What happens if you do nothing? The IRS says that if you do not reply, or it cannot resolve the difference, it may send another notice and a bill. Its tax topic on the CP2000 says that if it does not hear from you by the response date, it will send a statutory notice of deficiency (Letter 3219 or Notice CP3219A), sometimes called a “90-day letter.” Once that arrives, you generally have 90 days from its date (150 days if it is addressed to someone outside the United States) to petition the U.S. Tax Court. The Taxpayer Advocate Service says that window is set by law, the IRS cannot extend it, and trying to resolve things with the IRS does not extend it either. If you miss it, the proposed tax is assessed along with penalties and interest. Replying to the CP2000 on time is the easier, cheaper path.
Common mistakes
- Treating it as a bill and paying without checking. The IRS’s figures come from third-party reports. Sometimes those reports are wrong, duplicated, or missing your cost basis.
- Ignoring it because it “isn’t a bill.” No reply leads to a bill or a deficiency notice with fewer options.
- Filing a separate amended return without the response form. If you need to amend, the IRS says to mark Form 1040-X with “CP2000” and send it with your response.
- Sending originals. Send copies. Keep the originals.
- Missing the date because the letter sat unopened. The clock runs from the notice date, not the day you opened it.
- Replying to a scam. Confirm the notice is real before sending documents or money.
Where to get free help
- Taxpayer Advocate Service (TAS): An independent organization inside the IRS that helps people whose tax problems are causing financial difficulty or who have not been able to resolve things through normal channels. Free. Call 877-777-4778 or visit taxpayeradvocate.irs.gov.
- Low Income Taxpayer Clinics (LITCs): Independent clinics that can represent eligible people in disputes with the IRS, including CP2000 responses, for free or a small fee. Generally your income must be below a set level, and the amount in dispute is usually under $50,000. Find one through the LITC page or IRS Publication 4134.
- Your local IRS Taxpayer Assistance Center: In-person help. Call ahead for an appointment. Find yours through IRS.gov.
- A tax professional: If you hire one, the IRS says Form 2848 lets them represent you.
How Plainly helps
A CP2000 packs income tables, a tax calculation, and a response form into a few dense pages. Plainly turns it into plain English, quickly. Take a photo of your CP2000 (up to five pages) and Plainly tells you:
- What it is: which tax year it covers and which income the IRS thinks is missing from your return.
- What it wants from you: whether you need to agree, disagree, or send documents.
- Your deadline and how urgent it is: the reply-by date.
- The numbers that matter: the proposed change to your tax, including any penalties and interest.
- Anything that looks off: possible scam signals worth checking before you pay or call anyone.
- What it could not read: parts of your photo that were not clear, so you know what to double-check.
You can listen to the explanation read aloud, share it with someone who helps you, and find it later in My Scans on your device. It works on the web, iOS, and Android, needs no account, and Plainly does not store your photos.
Plainly can make mistakes, so check dates and amounts against your notice before you act.
Frequently asked questions
Is a CP2000 an audit?
No. The Taxpayer Advocate Service says a CP2000 “is not an IRS audit or a bill.” It is a proposal based on information that third parties reported. You can agree, disagree, or partly disagree.
How long do I have to respond to a CP2000?
Reply by the date printed on your notice. The IRS suggests replying within 30 days of the notice date (60 days if you live outside the United States). If you need more time, the IRS says you can send an extension request with a reply option.
Do I need to file an amended return?
Usually not. If you agree and have nothing else to report, you do not need to amend. If you have other income, credits, or expenses to report, send Form 1040-X marked “CP2000” with your response form.
What if I do not respond to a CP2000?
The IRS may send another notice and a bill. It says it will send a statutory notice of deficiency, which gives you a limited time (generally 90 days) to take the case to Tax Court before the tax is assessed.
Can I upload my CP2000 response online?
Yes. The IRS calls its document upload tool the fastest way to reply. You can also fax or mail it, using the location in the top left of your notice.
Plainly explains documents in plain language. It is not legal, tax, medical, or financial advice. Always check important dates, amounts, and contact details against the original letter.