when two people live together, their joint income, usually, is used to cover expenditure. if they split up and one person moves out, it creates a major financial problem. rent mortgage payments remain the same, as does home insurance, but now there is only one income to cover them. when a couple has a child, the situation becomes more complicated. the parent who has care of the child most of the time can claim financial support from the other parent. there might be additional childcare expenses if both parents now need to work full time has to get a part-time job.