Legal Question in Family Law in California

That language is terrible. It is basically meaningless. It says he pays $700/mo, but it is a credit toward child or spousal support (doesn't even make clear which). So all he really owes is whatever child and/or spousal support he would owe in the first place. The only relevant meaning that clause could seem to have by any rational interpretation is that he is supposed to be paying $700 of his child/spousal support obligation directly to the mortgage company. Other than that, the language would be surplusage. What it clearly does NOT say is that he owes $700 on top of whatever child/spousal support he owes. Which would be consistent with the law, which you have been correctly advised holds that your occupancy of the house is subject to rent owed to him, but is presumed to be equal to the cost of ownership you are paying, so it washes to zero absent evidence to the contrary. Bottom line is if he has paid anything to the mortgage company, he gets to deduct that from what he owes for child or spousal support (very important to distinguish the two because spousal is tax deductable to him, taxable to you, whereas child support is not deductable to him, and tax free to you). That is the only meaning of that phrase.