see note 136
Section 8 of the Federal Child Support Guidelines provides that, where each spouse or former spouse has custody of one or more children, the amount of a child support order is the difference between the amount that each would otherwise pay if a child support order were sought against each of them.137
Given possible future changes in the parental incomes, the parents may be
judicially directed to exchange complete copies of their income tax returns by 15 May of each year.138Where the parents earn the same income and each is responsible for the support of a child of the marriage, the court may decline to make any order for child support.139Bilateral orders may be granted for child support where each parent had custody of one or more children of the marriage.140Section 8 of the Federal Child Support Guidelines, unlike section 9, provides no judicial discretion in the assessment of child support.141Section 8 of the Federal Child Support Guidelines may be applied where each of the parents provides a home for one or more of their dependent children, even though one of the children is an adult attending university in respect of whom "neither parent has custody."142Section 8 of the Guidelines will not be satisfied, however, where the evidence is insufficient to establish that the adult child is a "child of the marriage" within the meaning of the Divorce Act.143Where parents have a split custody arrangement but the income of one of the parents falls short of the minimum threshold under the applicable provincial table, the other parent will be required to pay the full table amount of support for the child in the custody of the low- or no-income parent.144In addition to ordering payment of the differential between the two table amounts pursuant to section 8 of the Federal Child Support Guidelines, a court may order a sharing of special or extraordinary expenses under section 7 of the Guidelines in proportion to the respective parental incomes,145or in such other proportion as the court deems reasonable.146
 See, generally, Carol Rogerson, "Child Support under the Guidelines in Cases of Split and Shared Custody" (1998) 15 Can J Fam L 11 (on Quicklaw under Commentary, Syrtash Collection of Family Law Articles, SFLRP/1999-003).
 SEH v SRM,  BCJ No 1458 (SC) (split custody involving biological child and stepchild; set-off under s 8 of Federal Child Support Guidelines); Fitzpatrick v Fitzpatrick, ...