Are parents required to share income information every year for child support in Ontario?

Yes. Both the Federal and Ontario Child Support Guidelines include a mandatory annual income disclosure obligation. Each parent is required to provide the other with updated income information once a year, typically their most recent federal income tax return and Notice of Assessment, along with any other documents that show their current income.

This requirement exists because support is income-based and incomes change. Requiring annual disclosure is intended to keep support current without forcing families to go to court every time there is a small change. Parents can then negotiate adjustments informally or by a simple written amendment to their agreement, avoiding unnecessary applications.

Failure to provide annual income disclosure when required can have consequences. A court may draw adverse inferences, impute income, or award costs against a party who refuses or delays. In enforcement proceedings, courts look unfavourably on parties who have hidden income changes, especially if the other parent was underpaid as a result.

In practice, many families do not follow the annual disclosure rule unless one party pushes for it. If you suspect the other parent's income has changed significantly, you have the right to request updated financial disclosure. If they refuse, a motion for disclosure can be brought. A lawyer can help you pursue disclosure and determine whether a support variation is warranted.