My wife works for the irs, she doesn't deal with your type of things or audits etc, but she sent me this. Hope it helps
Understanding Your 5071C Letter
This letter tells you that the IRS received a tax return with your name and/or social security number and needs to verify your identity. You can verify your identity using our secure Identity Verification Service site at idverify.irs.gov. The contact information below is only for taxpayers who received Letter 5071C.
Why are we contacting you?
We received a federal income tax return with your name and/or social security number. We want to protect you from potential identity theft so we are asking you to verify your identity and tell us if you submitted the return. The letter you received provides two options for responding. Both options enable you to verify your identity with us so we can continue processing your tax return.
This contact information is only for taxpayers who received Letter 5071C. The toll-free number and website are for identity verification only. No other tax-related information, including refund status, is available.
What is involved in this process?
We will continue processing your tax return once we verify your identity and confirm that you submitted the return. If you did file the return, please know it will take approximately six weeks to process it once you verify your identity. Follow the identity verification described under "What should you do?" below to provide us with the necessary information.
What should you do?
Use our secure Identity Verification Service website idverify.irs.gov. It's quick and secure. You should have available a copy of your prior year tax return and your current year tax return, if you filed one, including supporting documents.
If you cannot use the Idverify website, you can call us using the toll-free Identity Verification telephone number provided in your letter. Again, you should have available a copy of your prior year tax return and your current year tax return, if you filed one, including supporting documents.
If you did not file the return in question, you can use either option to notify us.
How can I learn more about the IRS's identity protection efforts?
The IRS is continually looking at ways to increase data security and protect taxpayers' identities. To learn more, view these topics on IRS.gov.
Identity Protection: Prevention, Detection and Victim Assistance
Publication 4535, Identity Theft Prevention and Victim Assistance
