Unallocated child support refers to child support payments that are tax-deductible. If you are ordered to pay unallocated child support by a judge in court, all payments made will be tax-deductible.
All other kinds of child support payments are NOT tax-deductible for the paying parent, nor are they a taxable source of income for the receiving parent.
Unallocated child support will become past-due child support if the paying parent fails to make the payments on time.