Does a common-law parent have to pay child support in Ontario?

Yes. Child support is a right of the child and is not affected by whether the parents were married or in a common-law relationship. Both biological and legal parents have an obligation to financially support their children, regardless of their own relationship status.

Child support in Ontario is calculated using the Federal Child Support Guidelines, which base the amount primarily on the paying parent's gross income and the number of children. These guidelines apply equally to married and common-law parents. The parent with less parenting time typically pays the table amount; if parenting time is substantially shared (roughly 40% or more each), the calculation can be adjusted.

Special and extraordinary expenses — such as childcare, orthodontics, or extracurricular activities — are shared in proportion to each parent's income in addition to the base table amount. If you separate from a common-law partner and share children, the same support framework applies as for divorcing spouses. Either parent can apply to the Ontario court to establish or vary a support order. Voluntary agreements are also enforceable when properly documented.