Because an ITIN cannot be used for payroll purposes a preparer may receive a W-2 for an ITIN holder with an SSN that does not match the ITIN. Tax returns filed with an Individual Taxpayer Identification Number reporting wages paid are required to show the Social Security Number under which the wages were earned. The taxpayer's correct ITIN should be used as the identifying number at the top of Form 1040. (Use the ITIN when creating the tax return).  When inputting W-2 information, the SSN should be entered exactly as shown on the Form W-2 issued by the employer.  It is now possible to e-file a return with an ITIN/SSN mismatch.