What does this rejection code mean?
The IRS is stating that they have already accepted and processed a tax return for this year with that Social Security Number.
How do I fix my return?
To make certain that you entered your social security number correctly, log in to your account and go to the Basic Information Section >> General Information >> Personal Information.
If you did not file a federal return at all this year then you should contact the IRS immediately at 800-829-1040, as an income tax return has been filed using your social security number. The IRS also has an identity theft phone number which is 1-800-908-4490. Additionally, if you think you may be a victim of identity theft then you may want to contact your local authorities as well.