The other part you may be not "getting" is that in order to file as HOH, you must enter the SSN of the qualified dependent on your tax return. The qualified dependent for HOH cannot be the same child on both of your tax returns. You and your partner cannot enter the same SSN of your child (child AB) on each of your tax returns. That SSN can only be entered on one tax return. So.....the only way to file as HOH is to qualify as the custodial parent of either child A or child B and use that child's SSN on your tax return, saying that you and the other parent (the other parent of child A or child B) have a signed agreement regarding that child.
You began this post by wanting to exclude any other factors-----but now want to bring in the issue of your other children.
You might want to consult a local paid tax professional.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
