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What Is Undue Hardship in Ontario Family Law?

Understand undue hardship under the Federal Child Support Guidelines in Ontario: who can claim it, the listed circumstances and the limits.

Family Law5 min readTSLBy the Treadstone Law Team · OntarioUpdated November 6, 2026
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Key takeaways
  • Either spouse may ask the court for a child support amount different from the Guidelines amount if they or the child would otherwise suffer undue hardship.
  • The Guidelines list specific circumstances, such as unusually high debts or other support duties.
  • A claim must be denied if the claimant's household would have a higher standard of living than the other household.

If you pay or receive child support, you may hear that someone is claiming undue hardship. It sounds dramatic, but it is a specific, limited legal test.

This article explains what it means under the Federal Child Support Guidelines, who can raise it and why many claims do not succeed.

What undue hardship means

Under section 10(1) of the Federal Child Support Guidelines, either spouse may ask the court to award child support in an amount different from the Guidelines amount if the spouse or child would otherwise suffer undue hardship. It is a way to depart from the usual table amount in unusual cases.

Whether your situation qualifies depends on the facts, so it is worth confirming with a lawyer. The Guidelines name particular circumstances, and a court looks at the whole situation. Because either spouse can raise the issue, it can come up whether you are the person paying support or the person receiving it.

Circumstances the Guidelines list

CircumstanceSection
Unusually high debts reasonably incurred to support the spouses and children before separation, or to earn a living10(2)(a)
Unusually high expenses for exercising parenting time with a child10(2)(b)
A legal duty under a judgment, order or written separation agreement to support any person10(2)(c)
A legal duty to support another child who is not a child of the marriage10(2)(d)
A legal duty to support anyone who cannot obtain the necessaries of life because of illness or disability10(2)(e)

Whether your debts or expenses count as unusually high depends on the facts. A lawyer can help you assess this.

The household comparison limit

Even where undue hardship is found, the court must deny the claim if the claimant's household would have a higher standard of living than the other spouse's household after child support is set. The court may compare the two households using the test in Schedule II of the Guidelines.

In practice, this means a claim can fail even where the expenses are real. The comparison looks at both households, not just one.

Time limits and reasons

The court may set a reasonable time for the hardship-causing obligation to be satisfied, and the amount payable after that time. A hardship order may therefore be temporary. The court must also record its reasons for awarding a different amount.

Where the issue is raised and how it can be resolved

Generally, a family case starts in the municipality where you or your spouse lives. If parenting time or decision-making responsibility is involved, the municipality where the children live may apply instead. The Family Court Branch of the Superior Court of Justice (Unified Family Court) sits in 25 locations, including Barrie, Lindsay and Peterborough, and all family law issues can be heard there. Outside those locations, you start the case in either the Superior Court of Justice or the Ontario Court of Justice, depending on the claims. Both courts hear child and spousal support, but only the Superior Court of Justice hears divorce and property claims.

A case starts with an application (Form 8, 8A or a joint application). The respondent has 30 days to serve and file an Answer (Form 10), or 60 days if they live outside Canada and the United States, and the applicant has 10 days to file a Reply (Form 10A). Financial statements for support claims are on Form 13. The case then moves through a case conference, a settlement conference, a trial management conference and then trial, and the court guide gives no fixed timelines for these steps.

Not every disagreement has to be decided by a judge. If your case is a divorce proceeding, the Divorce Act requires parties to try to resolve matters through a family dispute resolution process, to the extent it is appropriate to do so. Legal advisers must encourage this unless it would clearly not be appropriate, for example where there is family violence. That includes negotiation, mediation and collaborative law. Mediation in Ontario is voluntary, and the mediator is a neutral third party who does not take sides, make decisions or give legal advice.

What to do next

If you are unsure where to start, Family Law Information Centres at family courts across Ontario give information on separation, divorce, alternative dispute resolution and court processes. How this applies depends on your situation, so it is worth confirming with a lawyer.

Frequently asked questions

Who can claim undue hardship?

Either spouse may ask the court for a different amount if the spouse or child would otherwise suffer undue hardship. It can be raised by the paying or the receiving parent.

Is having a new child a hardship?

A legal duty to support another child who is not a child of the marriage is one listed circumstance. It does not guarantee a change, and the household comparison still applies.

Can a hardship order be temporary?

Yes. The court may set a reasonable time for the obligation to be satisfied and the amount payable after that.

Why might a claim be denied?

The court must deny it if the claimant's household would have a higher standard of living than the other household after support is set.

Sources

Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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