Updated October 19, 2026. Quick answer: Letter 5071C belongs to the CP5071 series, which also includes CP5071 and CP5071F. It says a return was filed under your Social Security number or ITIN and asks you to verify your identity and the return. If the notice offers online verification, start at irs.gov/verifyreturn with your notice and tax records. If you did not file, you may be a victim of identity theft.
Quick reference
| Item | As the IRS describes it |
|---|---|
| Series | CP5071, 5071C and CP5071F |
| What it is | A request to verify your identity and a return |
| Online route | irs.gov/verifyreturn, if your notice provides online verification |
| Have ready | The tax return for the year on the notice, a prior year return, supporting documents |
| Form 14039 | Not needed if you verify, unless the IRS tells you |
| Time to allow for an IRS reply (Tax Topic 651) | At least 30 days |
| IP PIN Form 15227 route | Adjusted gross income below $84,000, or $168,000 married filing joint |
What the notice says
The IRS describes the series: the CP5071 series covers CP5071, 5071C and CP5071F.
“A federal income tax return, Form 1040 series, was filed under your Social Security number (SSN) or individual taxpayer identification number (ITIN).” The IRS asks you to verify your identity and the return. If you did not file, “Verify with us. You may be the victim of identity theft.” If you did file, you verify so the IRS can continue processing the return.
How to verify
“Follow the instructions on your notice to verify your identity and the tax return.” For the online route: “If your notice provides online verification, you can begin at: irs.gov/verifyreturn”
Have the notice and your tax records ready. If you filed, you need the return for the year on the notice, a prior year return if you filed one, and supporting documents for each return, such as a W-2, 1099 or Schedule C.
What the contact information is for
“The contact information on your notice is for identity and tax return verification only.” Other account details such as refund status may not be available through it.
If you verify your return, the IRS says you do not need Form 14039 unless it tells you to.
Protect your number
The IRS recommends an Identity Protection PIN to stop someone filing with your SSN or ITIN. For the phone and in-person versions of the same task, see Letter 4883C and Letter 5747C. Confirm the paper is real before you go online: is this IRS letter real.
Protect your number with an IP PIN
The IRS describes the protection: “An identity protection PIN (IP PIN) is a six-digit number that prevents someone else from filing a tax return using your Social Security number (SSN) or individual taxpayer identification number (ITIN).”
If you cannot set up an online account, the IRS offers a form route with an income test: “If your adjusted gross income on your last filed return is below $84,000 for Individuals or $168,000 for married filing joint and you can’t establish an online account, you can submit Form 15227, Application for an Identity Protection Personal Identification Number online.”
Where this comes from
The IRS page read for this page is the one titled Understanding your CP5071 series notice on irs.gov, as served on 2026-10-19. Your own notice controls: the dates, amounts and phone or fax numbers on it are the ones to use, and the IRS can update its page after we read it.
For IRS notices in general, Tax Topic 651 says “You should allow at least 30 days for a reply from the IRS.” It also says “Keep a copy of all IRS correspondence for your tax records.”
Common mistakes
- Searching for a verification site. The IRS gives one address, irs.gov/verifyreturn, and only if your notice offers online verification.
- Filing Form 14039 before verifying. The IRS says it is not needed if you verify, unless told.
- Using the verification contact for refund status.
- Skipping the prior year return. The IRS lists it as something to have ready.
Related: IRS Letter 4883C, IRS Letter 5747C, is this IRS letter real, and IRS notices and letters.
Sources
- IRS, Understanding your CP5071 series notice, covering Letter 5071C (irs.gov): https://www.irs.gov/individuals/understanding-your-letter-5071c-or-6331c
- IRS, Get an Identity Protection PIN (IP PIN) (irs.gov): https://www.irs.gov/identity-theft-fraud-scams/get-an-identity-protection-pin
- IRS, Tax Topic 651, Notices: what to do (irs.gov): https://www.irs.gov/taxtopics/tc651
Read from the IRS pages linked above on October 19, 2026. General information, not tax or legal advice. Your own notice and facts decide the outcome, and the number printed on your notice is the right place to confirm anything consequential.