CanadaWhat constitutes a 'material change in circumstances' to vary a support order?
A 'material change in circumstances' is a significant, unforeseen, and ongoing change that would likely have resulted in a different support order had it existed at the time of the original decision.
What the Law Says
The Divorce Act sets the legal test for changing an existing support order — you must prove a 'material change in circumstances'. This is the threshold requirement before a court will even consider varying the amount or terms of support.
Under section 17 of the Divorce Act, a court may vary, rescind, or suspend a support order only 'on proof of a material change in circumstances'. This applies to both child and spousal support orders made under the Act.
The phrase 'material change in circumstances' is not defined in the statute, but courts have interpreted it consistently: the change must be substantial, ongoing, and something that was not reasonably foreseeable when the original order was made.
It is not enough that one party’s finances have improved or declined slightly — the change must be significant enough that, if known at the time of the original order, it would likely have led to a different result.
Statutory TextCourt may vary, rescind or suspend a support or parenting order on proof of a material change in circumstances.
— Divorce Act, s. 17 — Variation orders
What Courts Have Said
The Supreme Court of Canada recently clarified the meaning and application of 'material change in circumstances' in a landmark spousal support variation case.
The Court reaffirmed that a material change must be 'substantial, continuous, and unforeseen' — not merely a fluctuation in income or temporary hardship. It emphasized that the focus is on whether the change undermines the 'continued appropriateness' of the original order.
What to Do
Gather clear evidence (e.g., tax returns, medical reports, job loss documentation) showing the change is real, significant, and lasting.
Confirm the change was not reasonably foreseeable when the original order was made.
File a variation application in the appropriate court (usually where the original order was made or where either party resides).
Be prepared to show how the change affects the original support objectives — e.g., need, ability to pay, or the parties’ roles during marriage.
Sources
Not legal advice. This article is general information based on publicly available sources, written for educational purposes. Laws change and individual situations vary. Consult a licensed attorney in your jurisdiction before acting on anything you read here. Last reviewed: 2026-06-08.