“개인 w2 세금보고를 못했을 경우 어떻게 되나요?”----->If you already filed your return, then, you need to revise your tax return by filing form 1040X with the IRS. So, you need to use Form 1040X, along with a new Form 1040, plus any other necessary schedules and forms. Amended tax returns have to be mailed to the IRS on paper for manual processing.( If you didn’t file your 2011 return yet)If you owe taxes and didn’t file your tax return or request an extension by the April 12, 2012 deadline, you may face interest on any unpaid federal taxes you owe and a failure-to-file penalty. The IRS will deny a request for an extension that is filed after midnight on April 17. However, you should still file your tax return, even if it’s late.