Child Support Forms ; 4-3a. Petition (Commissioner).5 For the tax year, have you paid an amount in child support equal to or more than the amount due for every order requiring you to make child support payments? OCSS services include assistance with locating noncustodial parents, establishing parentage, establishing child support and medical support orders. Note: This form also applies to some tax benefits, including the child tax credit, additional child tax credit, and credit for other dependents. There is not a child support tax deduction available. Instead, the amount of child support you provide usually doesn't matter. This online program from Family Legal Care guides you through filling out a Petition for Child Support. The written declaration must be made in a format that follows a particular form. Complete the form, attach all required documents, and mail it to the appropriate Child Support Office.