Material change in circumstances - the test in Ontario

A "material change in circumstances" is the legal test for changing an Ontario support or parenting order: a change that is significant, was not foreseen when the order was made, and would likely have led to a different order had it been known at the time. All three conditions have to be true. The test comes from the Supreme Court of Canada's decisions in Willick v Willick (for child support) and Gordon v Goertz (for parenting). It is the gatekeeper for any variation — without a material change, you do not get back to the order, no matter what the new amount or schedule would be.

The same test applies under the Divorce Act (section 17) and the Family Law Act (section 37 for support, section 29 of the Children's Law Reform Act for parenting). Ontario courts apply it consistently across all three.

When this does apply

The material-change test applies any time you are trying to change an existing support or parenting order. For support, qualifying examples: a real income change (up or down) — typically 15% or more from the income used to set the original order, and lasting rather than temporary. A child aging out of support. A change in the parenting arrangement that affects the Federal Child Support Tables calculation. A new dependant the payor is supporting. For parenting, qualifying examples: relocation, a major work-schedule change, a change in the child's needs or age, a serious safety issue. In each case the change must (a) be significant, (b) not have been foreseen when the order was made, and (c) be the kind of change that would likely have produced a different order.

When this doesn't apply

A temporary income dip — a bad quarter, a brief layoff with a return-to-work date — does not meet the test. A change you knew about when the original order was made does not qualify either — if you foresaw the income change, you cannot raise it later as a material change. Wanting a different amount, disagreement with how the recipient is spending the money, a new partner contributing to the household, general dissatisfaction with the original order — none of these qualify. Courts are skeptical of variation applications brought in the first year after an order, where the underlying circumstances have not actually changed: judges read them as a parent trying to relitigate the original decision rather than respond to a new fact.

What to do

State the change in one or two sentences. If you cannot, the court will not see it either. Then ask three questions: (1) Is this change significant in size, or is it minor? (2) Was this change foreseeable when the original order was made? (3) Would the court have made a different order if it had known? If the answer to (1) is "significant," (2) is "no, this is genuinely new," and (3) is "yes, the order would have been different," you have a material change. Document the evidence (T4s, pay stubs, school records, work schedule changes, medical reports, whatever is concrete), then proceed to the variation application — see how to change a child support order, how to change a parenting order, or how to change a separation agreement.

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