The IRS reject code F540/2EZ-1010 identifies when the Social Security Number or the Taxpayer Identification Number of the filer is used on another federal income tax return.
This rejection code may also be shown on state income tax returns. You can solve this problem by saving your Social Security Number or TIN within the tax preparation software and contact the IRS. Again, if this is about your state income taxes, contact the state department for taxation and let them know about this issue. Another taxpayer with a similar SSN/TIN to yours may have filed their taxes and entered your taxpayer identification number instead of theirs.
The IRS can then resolve the issue and you can file your tax return without getting the F540/2EZ-1010 rejection code. This rejection may also appear as F540/NR/2EZ-320 rather than above but point out the same issue.