In its efforts to combat identity theft, the IRS is stopping suspicious tax returns that have indications of being identity theft, but contain a real taxpayer’s name and/or Social Security number, and sending out Letter 5071C to request that the taxpayer verify his or her identity.
Letter 5071C is mailed through the U.S. Postal Service to the address on the return. It asks taxpayers to verify their identities in order for the IRS to complete processing of the returns if the taxpayers did file it or reject the returns if the taxpayers did not file it.
It is important to understand that the IRS does not request such information via e-mail; nor will the IRS call you directly to ask this information without first sending you a Letter 5071C. The letter number can be found in the upper corner of the page.
Letter 5071C gives you two options to contact the IRS and confirm whether or not you filed the return: You can (1) use the www.idverify.irs.gov site or (2) call a toll-free number on the letter. However, the IRS says that, because of the high volume on its toll-free numbers, the IRS-sponsored website, www.idverify.irs.gov, is the safest, fastest option for taxpayers with Web access.