Is it possible for two people to use the same child for benefits? One person is the parent and the other person is the boyfriend. They are not married.
Parent claims the child as a dependent BUT files single
The parent's boyfriend claims HOH but doesn't claim the child dependent
Then I dont think your scenario works...I dont see this often, and its not that straightforward (no simple keywords) to just look up, but Im pretty sure when they live together you can't split the benefits like that.
Your original question stated you wanted the boyfriend to claim Head of Household. Then you later seemed to be asking if the mother can claim Head of Household.
???
One of the requirements of Head of Household is paying for over 50% of the cost of keeping up the home. You seem to be arbitrarily trying to claim Head of Household without really looking at the facts or requirements.
