Is your CP2000 real? How to check it comes from the IRS
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Is your CP2000 real? How to check it comes from the IRS
By Tax Letter Desk Updated November 4, 2026
Short answer
A real CP2000 sets out what you reported, what each payer reported and the proposed changes.
It comes with a Response form, an envelope and a list of payment methods.
If it looks suspicious, call the IRS at 800-829-1040.
Checked November 4, 2026 against IRS Topic 652 (Oct 16, 2026) , IRS notices page (May 26, 2026) .
In this article
What’s in a real CP2000?
Where’s the notice number?
Do the fax numbers match?
What if it looks suspicious?
How do I reply safely?
Questions
What’s in a real CP2000?
The amounts you reported.
The amounts each payer reported.
Each payer’s name and ID number, and the form type.
The proposed changes to income, tax, credits or payments.
A Response form, an envelope and payment methods.
The first page also gives a phone number and the steps to respond.
Where’s the notice number?
On the right corner of the letter. Search it on the IRS notices page.
See which reply your notice needs before you pay anything.
Do the fax numbers match?
The IRS lists the fax number of each office that sends CP2000s. Your notice names its office on the top left.
What if it looks suspicious?
If the letter doesn’t appear in the IRS search, or looks suspicious, call 800-829-1040.
Follow the IRS representative’s instructions.
How do I reply safely?
Use the IRS Document Upload Tool, or the fax number or address on the notice.
If you fax online, check the service’s privacy and security policies.
Sources
Topic no. 652, Notice of underreported income, CP2000 IRS, updated October 16, 2026
Understanding your IRS notice or letter IRS, updated May 26, 2026
Understanding your CP2000 series notice IRS, updated July 14, 2026
Questions
800-829-1040, per the IRS page on notices and letters.
On the right corner of the letter.
Yes. A Response form, an envelope and a list of payment methods.
Related guides
How to respond to a CP2000 notice Pillar guide
How to send your CP2000 response Guide
CP2501 vs CP2000: what each letter asks Article
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