- On application, a court may set aside a domestic contract on three grounds: failure to disclose significant assets or debts, not understanding the contract, or the general law of contract.
- A clause in the contract cannot take away the court's power to set it aside.
- Even a valid contract does not bind a court on some child and support matters.
You signed a marriage contract and now you regret it. Perhaps you feel you were not told everything, you were rushed, or the result seems unfair. The first question is whether the law gives you a way out.
Ontario courts do have power to set aside a marriage contract, but only on limited grounds. This article explains them in plain language. Whether they fit your facts is something a lawyer should assess.
The three grounds in section 56(4)
Under s. 56(4) of the Family Law Act, a court may set aside a domestic contract, or a provision in it, on application. Regret alone is not one of the listed grounds. The grounds are set out below.
| Ground | What it means |
|---|---|
| Non-disclosure (s. 56(4)(a)) | A party failed to disclose significant assets, or significant debts or other liabilities, existing when the contract was made. |
| Lack of understanding (s. 56(4)(b)) | A party did not understand the nature or consequences of the contract. |
| Law of contract (s. 56(4)(c)) | The contract can be set aside otherwise in accordance with the law of contract. |
Pressure, duress and unfairness
The Act does not name duress or pressure to sign. Those arguments are generally made under the law of contract ground. Courts decide them case by case, so the details of how and when you were asked to sign matter.
Unfairness on its own is not listed as a ground. Unfair terms may support an argument under one of the listed grounds, for example if you did not understand what you were giving up, but that depends on the facts.
A contract cannot protect itself. Subsections 56(4), (5) and (6) apply despite any agreement to the contrary, so a clause that says you cannot challenge the contract does not remove the court's power.
Terms a court may not enforce even if the contract stands
- Children: a court deciding education, moral training, decision-making responsibility or parenting time may disregard a contract provision if that is in the child's best interests.
- Child support: a court may disregard a provision that is unreasonable having regard to the child support guidelines.
- The matrimonial home: any term limiting a spouse's Part II rights is unenforceable.
- Chastity clauses: a term ending a party's rights on separation if that party is not chaste is unenforceable, although a term ending rights on marriage or cohabitation with another person is still given effect.
Support waivers get extra scrutiny
Under section 33(4) of the Family Law Act, a court may set aside a support provision, or a waiver of the right to support, in a domestic contract on three grounds: the provision or waiver results in unconscionable circumstances, it is in favour of (or the waiver is by or on behalf of) a dependant who qualifies for support out of public money, or support under the contract is in default when the application is made.
- It results in unconscionable circumstances.
- It is in favour of, or the waiver is by or on behalf of, a dependant who qualifies for an allowance for support out of public money.
- Support under the contract is in default when the application is made.
If you are divorcing, the federal Divorce Act also treats an agreement about support as a factor the court weighs, not a bar to support.
What to do next
Collect your copy of the contract, any drafts, emails or messages about signing, and whatever financial information was exchanged. Write down what you were told about the other person's assets and debts, and what you understood at the time. Then speak with a family lawyer soon, because a lawyer can confirm any time limits and whether your facts fit a ground. If support under the contract is unpaid, the contract can be filed with the court clerk for enforcement.
Frequently asked questions
Can I set aside a prenup just because I regret it?
Regret alone is not a listed ground. A court may set a contract aside if a party failed to disclose significant assets or debts, did not understand the contract's nature or consequences, or on grounds under the law of contract.
Does a clause saying I waive my right to challenge the contract work?
No. The court's power to set aside a contract applies despite any agreement to the contrary.
Can a court change what the contract says about child support?
Yes, in some cases. A court may disregard a child support provision that is unreasonable having regard to the child support guidelines.
Does the same law apply to a contract signed outside Ontario?
Formalities and validity are governed by the contract's proper law, but sections 33(4) and 56 still apply in Ontario.
Sources
- Family Law Act, s. 52(2) — Ontario e-Laws
- Divorce Act, s. 15.2(4)(c) — Justice Laws (federal)
- Ontario.ca – Spousal support — ontario.ca
Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.
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