Hi,
This is for my tax year 2010. I filed jointly and I reported all the income we had (W2,INT1099). Couple of days ago I got a letter from IRS saying I didn't report 55,000 that's on my W2. The fact is there's no such income for us for that year. What I have to do now? Anyone experienced this problem?

First, request a copy of your tax transcript for 2010.

It will have your joint 2010 tax return and ALL tax documents that were submitted to them with your SSN on it. That may identify the reason why the IRS says you got $55K that you seem to think you did NOT get. If there IS a phantom W-2 out there, the transcript will identify the company that issued the W-2 by name, address and tax ID #. You can then contact them and get the matter resolved. It is LIKELY the offending W-2 has a data error on the SSN, and the incorrect SSN matched your SSN by sheer dumb BAD luck.

Once you identify the problem to the offending company, they will correct the error by issuing a corrected W-2 (called a W-2C) and the problem with the IRS should go away.

While you are at it, you probably will want to clue in the STATE tax agency in the state where you worked and lived, because, if you do not let them know about this, THEY EVENTUALLY will send you a notice as well asking for thates on that mysterious $55,000 you earned and did not claim on the STATE tax return.