Report Fraud: Tax I.D. Theft Page Article If you get an IRS notice in the mail, call the IRS right away. Complete IRS Form 14039, Identity Theft Affidavit . Mail or fax the form according to the instructions. Include proof of your identity, like a copy of your Social Security card, driver’s license or passport. Did the notice say you were paid by an employer you don't know? Send a letter to the employer explaining that someone stole your identity, and that you don’t work for the employer. File your tax return, and pay any taxes you owe. You might have to mail paper tax returns. Write down who you contacted and when. Keep copies of any letters you send. If these steps don’t resolve your situation, contact the IRS’s Identity Protection Unit at 1-800-908-4490.