Does the Payor's New Children Reduce Idaho Child Support?

Attorney Answer

His three new children can reduce what he pays — but only because you have no court order. If a support order had already been entered, children born afterward would be excluded from the calculation entirely.

That is the whole answer to your question, and it turns on a distinction the guidelines draw sharply. The Idaho Child Support Guidelines are Idaho Rule of Family Law Procedure 120. Section (f)(4) allows a deduction from a parent's gross income for a natural or adopted child of another relationship who resides in that parent's home. Section (f)(5) then provides that children who are born or adopted after the entry of the existing order will not be considered — so on a motion to modify an existing order, later-born children are off the table.

You and your ex have had only a verbal agreement for three years. That means there is no existing order, so nothing is being modified. A court asked to set support now would be entering an initial order under the guidelines, and on an initial order the (f)(4) deduction is available to him for children of another relationship living in his home.

So go in clear-eyed. The number a court sets may be lower than what he verbally promised you, particularly with a shared 50/50 schedule, which the guidelines already account for. What you gain is the thing you do not have now: a fixed amount, a due date, an obligation that does not depend on his goodwill, and the enforcement machinery — income withholding, arrears that accumulate, and contempt — that a handshake cannot give you. A verbal agreement he is 'falling short' of is not something a court can enforce.

One timing rule to carry forward. Once an order exists, Idaho Code § 32-709 permits modification only on a showing of a substantial and material change of circumstances, and only as to installments accruing after the motion for modification is filed. The filing date, not the date the circumstances changed, is what limits how far back any change reaches — in either direction.

What you can do

1. Decide, knowing the number may go down, whether you want an enforceable order. In most cases the answer is yes, because an unenforceable promise is worth nothing when payments stop. 2. Gather income documentation for both of you — recent pay stubs, W-2s, and the last two years of tax returns — plus your child's actual costs, especially childcare and health insurance premiums. 3. Open a case with Idaho Child Support Services, or file in the magistrate division of the county where your child lives, to establish support. 4. Document the 50/50 schedule as it is actually exercised, not as it was agreed. Overnights drive the guideline calculation, and if the real split differs from the nominal one, that changes the number. 5. Keep a written ledger of what he has actually paid over the three years, with dates and amounts, and ask the court or the agency what, if anything, can be addressed from the period before an order. 6. When an order enters, use income withholding from the start rather than relying on direct payment. 7. If his income or the parenting schedule changes later, file the modification motion promptly — under § 32-709 the change only reaches installments accruing after you file.