Combined child support income

Combined child support income is the sum of the parents’ incomes after subtracting a self-support amount for each parent. The formula treats this amount as the total income available to support children.

From cost tables, combined income is used to determine the cost of the children. It establishes an aspirational standard of living for children based on the parents’ total financial capacity.

Role in the formula

Combined child support income is calculated after each parent’s child support income is worked out. Child support income is adjusted taxable income (ATI) minus a self-support amount and any further case-specific deductions.

The self-support amount is annually set to one-third of Male Total Average Weekly Earnings (MTAWE). It ensures each parent keeps a base level of income before contributing to child support.

The combined figure is then used at a later step to determine the costs of the children. This is where it becomes pivotal to the outcome of the assessment.

How combined income sets the cost of children

The formula uses combined child support income to select a cost level from the Costs of the Children tables. These tables are based on research into how much families at different income levels spend on children.

As combined income increases, the total cost assigned to the children increases. The percentage applied gradually decreases at higher income levels, and the total cost is capped once income exceeds a threshold.

Example cost of children (1 child aged 0–12)

This structure shows how the formula sets an income-based standard of living. Children are treated as sharing in the financial position of both parents, rather than being supported at a uniform or minimum level.

Income percentage

Combined income also serves as the denominator when calculating each parent’s income percentage. The result represents the share of financial responsibility the parent carries based on their relative income.