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 or Individual Taxpayer Identification Number. The IP PIN is known only to you and the IRS. It helps the IRS verify your identity when you file your electronic or paper tax return. Even though you may not have a filing requirement, an IP PIN still protects your account.
Visit the IRS “Get An Identity Protection PIN” page.
Read the IRS IP PIN FAQ page.