When a couple living in a household without being married/partnered have one or more children of their own, then the common child is deemed to be part of the household of the taxpayer who received the first payment of child benefit.  If the child is in receipt of a state grant for higher education or volunteer aid, or if no grant or aid has been awarded, the joint children are deemed to be part of the household of the parent who, in the previous tax year, benefited from the child benefit.