IRS notice CP5071: what the CP5071, 5071C and CP5071F versions ask of you

What the IRS notice CP5071 series is

The IRS notice CP5071 series is the family of identity and return verification notices the IRS mails when a Form 1040 series return filed under your SSN or ITIN needs confirming before it is processed. The notice asks you to prove two things: that you are the taxpayer, and that the return is really yours.

The IRS keeps one explanation page, titled Understanding your CP5071 series notice, that covers three labels: CP5071, 5071C and CP5071F. The Taxpayer Advocate Service also treats Letter 5071C as part of the CP 5071 series. The IRS page was last reviewed on March 17, 2026, and older IRS addresses for Letter 5071C and for CP5071C now redirect to it.

For how this series fits with the other identity letters (4883C by phone, 5747C in person), see our identity verification hub.

Is CP5071 replacing Letter 5071C?

In practice, the IRS now treats them as one series rather than separate products. Its older page for Letter 5071C now redirects to the CP5071 series page, and the online verification service names the CP5071 series notice, not Letter 5071C, as one of the two notices it accepts.

What matters for you is that the response steps are the same whichever label is printed on your paper. The IRS has not announced a separate process for any one version, so follow the instructions on your own notice.

CP5071 vs CP5071C vs CP5071F

The IRS does not publish a public breakdown of what separates each suffix. Its page gives one set of instructions for all three and tells you to follow the directions on your notice. Treat the version code as a label for the IRS's internal routing, and read your own notice for the method it offers.

How to verify a CP5071 online: the IRS verify return online service

The IRS says that if your notice provides online verification, you begin at irs.gov/verifyreturn. That address leads to the Identity and Tax Return Verification Service, which accepts CP5071 series notices and Letter 5447C only.

1. Check your notice for the online option. If it gives only a phone number, use the phone number.
2. Put your copy of the return for the notice year next to you, along with the prior-year return and the W-2s, 1099s and any Schedule C or F.
3. Go to irs.gov/verifyreturn and sign in, or create an account if you do not have one.
4. If you were sent back to the start after creating an account, sign in again; the IRS says this can happen.
5. Answer the questions about the return and state whether you filed it.
6. Save or print the confirmation screen before closing the window.

The online service is not open to anyone under 18, who must contact the IRS by the method on the notice. Once you have verified, the IRS says you do not need Form 14039, Identity Theft Affidavit, unless it specifically asks for one.

Using the contact on the notice instead

The IRS stresses that the contact information printed on a CP5071 series notice is for identity and return verification only. Refund status and other account questions may not be available through it, so use Where's My Refund or your online account for those.

If you did not file the return on your CP5071

The IRS wording is direct: if you did not file, verify with the IRS anyway, because you may be a victim of identity theft. The online service lets you report that a return filed under your number is not yours.

1. Respond through the online service or the contact on the notice and say you did not file.
2. Do not also file Form 14039 unless the IRS tells you to.
3. Keep copies of the notice, your confirmation screen or call notes, and any later IRS letters in one folder.
4. Plan ahead for next year by requesting an Identity Protection PIN, a 6-digit number that changes every year; e-filed returns under your SSN are rejected without it.

Expect this track to be slow. The National Taxpayer Advocate's 2026 mid-year report found identity theft victim assistance cases took about 20 months to resolve, with more than 500,000 cases still pending when the filing season ended. If a related e-file rejection is blocking you, see our page on a return rejected for a missing or wrong IP PIN.

What happens after you answer a CP5071 series notice

Verified returns go back into normal processing. The online service says to wait 2 to 3 weeks before checking your refund and allows up to 9 weeks for processing. Our guide to refund timing after identity verification shows what to watch for during those weeks.

If you received a different verification letter with a similar look, such as Letter 6331C, read our Letter 6331C page before responding, since its instructions may differ.