Any employer you work for during a tax year must send you a W-2 form by Jan. 31 of the following year. This form shows your gross wages, withholdings and other details of your compensation and deductions. The employer must also send a copy of the W-2 to the Internal Revenue Service so it can confirm your income information when you file your tax return.

Matching W-2

When you enter W-2 income details and submit your return, the IRS compares your name and Social Security number to the same information on the W-2 copies it received from your employers. A mismatch typically results in an inquiry or mail audit, as the IRS wants to know the reason for the discrepancy. In some cases, preparers make simple errors that result in the mismatch. Major discrepancies may attract more attention if the IRS is concerned about tax fraud.