What this letter is about Letter 4310C is telling you someone may have attempted to impersonate you by using your name and social security number (SSN). Why We're Contacting You Through processing safeguards, we resolved the issue. We adjusted your tax account to show the correct return information. We also placed an indicator on your tax account to flag all tax returns submitted with your SSN as a possible identity theft case. We'll review those returns to ensure someone else isn't using your SSN to file a tax return. What you need to do If you have already filed your tax return for the tax year indicated on your letter, you don't need to submit anything to us at this time. If you have not filed your tax return for the tax year indicated on your letter, you must file a paper return by mail to the Internal Revenue Service Submission Processing Campus that services your state. Please follow the instructions in the letter. Please continue to file your subsequent federal tax returns as you normally would. If we have any issues with processing your returns, we'll contact you. However, we won't use e-mail to initiate contact with you or request personal information. If you notice any suspicious or unusual activity on any of your financial accounts, follow the steps as provided in Publication 5027, Identity Theft Information for Taxpayers PDF (PDF). You may want to Register for an Identity Protection Personal Identification Number (IP PIN) for future filings. An IP PIN is a unique 6-digit number that helps us verify your identity and accept your electronic or paper tax return. You will receive your IP PIN in a notice from us in December. If you want to receive the additional security of an IP PIN immediately, visit Get an IP PIN; verify your identity, and we’ll assign an IP PIN to file your returns. How you can 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 Identity Theft Central. How to get help If you have questions you can call our ID Theft line at 800-908-4490, (Monday - Friday 7 a.m. - 7 p.m. local time; Alaska and Hawaii follow Pacific Time).