IRS Reject Code SEIC-F1040-506-03
Each 'QualifyingChildSSN' that has a value on Schedule EIC (Form 1040), must not be equal to another Qualifying Child SSN on another accepted return for the same tax year.
This reject occurs when the taxpayer's qualifying child claimed for the Earned Income Credit has already been claimed for the EIC by another taxpayer.
This return will not be e-fileable unless the dependent is removed from the return or the return is filed indicating that the taxpayer doesn't qualify for the EIC. Alternatively, if the taxpayer believes they are entitled to claim the dependent for EIC purposes they can file the return in paper form including an explanation.
Additional Information: