Where do I start to look for, "How to find out who been using my Social Security number in a Tax return"

Answer 1

There is no way for you to find that information out. That would be disclosing another Taxpayers information to you and that in itself is illegal to do.
If someone used your social security number and it is making it that you have to file a paper return. You will get a letter from the IRS stating that 2 people used the SS#, and requesting proof of who that number belongs to and eligibility to claim you .
Respond to that notice as soon as possible to expedite the processing of your return
for more information call the Internal Revenue Service at
1-800-829-1040

Answer 2

You usually can't find out who did that. If there's a problem with your return, the IRS will be in touch.

Twice over the years I had someone use my SSN for employment purposes. One had a bogus name but the scary one had my correct name. (This was back in the 1980s, long before anyone heard of "identity theft").

On both occasions the IRS contacted me questioning the amount of income claimed on my returns. The one with the bogus name was clear across the country and I cleared it up on the phone. The other one was local to where I was living -- probably someone went dumpster diving at the apartment complex where I lived. I had to go to the local IRS office and eventually signed a sworn statement under penalty of perjury that the income was not mine.

If you try to e-file and your return is rejected as already filed or claimed as a dependent on another return you have to file a paper return and wait for the IRS to sort it out. They won't tell you who the other party was due to privacy and security laws.

Answer 3

You can go on the internet at www.irs.org or what I would do is either write them or call. Internal Rvenue Service
Kansas City, MO 64999-0025
1 [phone]
And if there is somebody using your sss# on taxes you better pres- charges on whoever the person is. That's fraud BIG TIME!!! and somebody will pay for that.