What to do if your W-2 is wrong
By now you should have received most, if not all, of your W-2s from 2011; employers are required to provide the forms by Jan. 31. The first thing you should do when you receive a W-2 is to check the figures against your records to make sure the reported amounts are correct.
Using your final pay stub from last year, carefully compare the gross federal and state wages, federal, state and local income tax withheld, and Social Security and Medicare taxes withheld with the figures on the W-2s. Also be sure to verify that the Social Security number on the W-2 is correct. This is perhaps the most important number on the form.
If you find an error or discrepancy, contact the employer, which will issue a corrected W-3c and W-2c to the Social Security Administration (employers send W-2s to the SSA and not the IRS, although the IRS eventually gets the information for matching) and send copies of the corrected W-2c to you. Attach Copy B of the W-2c to your tax return, along with the original erroneous W-2, when you send it in.
While you should also notify your current employer if you find an error or typo in your name or address, such errors should not affect your tax filing and should not require a new W-2.
If you don’t receive a W-2 and can’t contact the employer because it has gone out of business or disappeared, all is not lost. You can use your pay stubs or other records from that job to reconstruct the various items of income and withholding and file Form 4852 (.pdf file), the Substitute for Form W-2 Wage and Tax Statement, with your federal and state tax returns.
Of course, you should also verify that the Social Security and income numbers reported on 1099s you receive for interest, dividends or miscellaneous income are correct as well.