IRS Identity Protection PIN

If taxpayer, spouse, or dependent experienced IRS-related identity theft (a fraudulent tax return was filed using their SSN/ITIN) and previously worked with the IRS to fix this, the IRS will issue a CP01A letter with an IP PIN for e-filing. The IRS sends a new IP PIN letter each year before the tax season; this PIN must be used for all e-filed returns during the calendar year, regardless of tax year of the [amended] return.

The taxpayer should mark “Yes” on Page 1 of the Intake Booklet for “… been a victim of tax related identity theft or issued an Identity Protection PIN?”

Residents of all states can also voluntarily apply online to get an IP PIN, as described in Pub 5367, Identity Protection PIN Opt-in Program for Taxpayers. Then, each year they must obtain a new IP PIN through their account at irs.gov/ippin.
For a MFJ return, enter the IP PIN only for whoever was issued the IP PIN on the IRS letter. (But check to see if both the taxpayer and spouse have an IP PIN.)
An IP PIN is entered on the IRS Identity Protection Pin page, which can be reached in two ways.

New: TaxSlayer now has an e-file warning if there was an IP PIN on the prior return but not the current return.
If the taxpayer received an IP PIN but can’t find it, there are three options:

The taxpayer can call the IRS ID Theft hotline, 800-908-4490, to get the IP PIN reissued. The IRS mails the IP PIN to the taxpayer’s address of record within 21 days.
The taxpayer can go online (to irs.gov/ippin ; click “Get an IP PIN”) and, by accessing or creating an account (see above), retrieve their IP PIN.
If the taxpayer can’t retrieve or get a new IP PIN, the return must be paper-filed (create a note - page 8 - saying that).

More information can be found on Pub 4012 page P-5, “IP PIN Guidance for Identity Theft Victims.”