- In Ontario a prenup is a marriage contract, and it is unenforceable unless it is in writing, signed by the parties and witnessed.
- Once it is validly signed, the couple must follow it, but a court can set it aside on specific grounds.
- Some terms, including those on children and on support, can be overridden by a court.
If you are considering a prenup, the main question is probably whether it will hold up. In Ontario, a properly made marriage contract is generally followed, but it is not untouchable.
This article explains what makes a prenup valid, when a court can set one aside, and which terms a court may override even in a valid contract.
Are prenups legally binding in Ontario?
Prenup is an informal name, and the Family Law Act calls the document a marriage contract. Ontario's government guidance says that once a marriage contract is signed, the couple must follow it.
A contract that deals with a matter also dealt with in the Family Law Act prevails over the Act, unless the Act provides otherwise. For property, the Act lets spouses agree by a domestic contract that certain property is not included in net family property. So a prenup can change the default property rules.
What makes a prenup valid
A domestic contract, and any agreement to amend or rescind one, is unenforceable unless it is made in writing, signed by the parties and witnessed. Ontario's government guidance adds that the witness must also sign.
- It is in writing.
- Both people sign it.
- A witness is present, and the witness also signs.
- The people have the capacity to sign, or someone legally able to act signs for them.
On capacity, a minor can enter into a domestic contract, but only with the court's approval. For a mentally incapable person, a guardian of property or an attorney under a continuing power of attorney for property may enter into the contract. In other cases of mental incapacity, the Public Guardian and Trustee has power to act.
Do you need a lawyer?
None of the formal requirements for validity is a lawyer. Even so, Ontario's government advises that each partner speak to a different lawyer and that the partners exchange financial information before signing. How this applies depends on your situation, so it is worth confirming with a lawyer before you sign anything that settles your rights.
When a court can set a prenup aside
On application, a court may set aside a domestic contract, or a provision in it, on three grounds.
| Ground | Plain meaning |
|---|---|
| Non-disclosure | A party failed to disclose significant assets, or significant debts or other liabilities, existing when the contract was made. |
| Lack of understanding | A party did not understand the nature or consequences of the contract. |
| Contract law | The contract can be set aside otherwise in accordance with the law of contract, which is the route for arguments such as duress or pressure to sign. |
A clause in the contract cannot remove the court's power to set it aside. How a court treats questions of timing or pressure depends on the facts, so get legal advice if that concerns you.
Terms a court can override even if the prenup is valid
- Children: a court deciding education, moral training, decision-making responsibility or parenting time may disregard a provision if doing so 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.
- Spousal support: a court may set aside a support provision or a waiver if it results in unconscionable circumstances, if a waiver is by or for a dependant who qualifies for support out of public money, or if support under the contract is in default.
- Matrimonial home: a term that tries to limit a spouse's rights under Part II is unenforceable.
What to do next
If you want a prenup to be reliable, treat the process as seriously as the document.
- Make a full list of your assets and debts and share it with your partner.
- Each of you should speak to a different lawyer.
- Do not rely on terms that Ontario law will not enforce.
- Sign in writing in front of a witness, and keep copies.
Frequently asked questions
Will an Ontario court always enforce a prenup?
Not always. A court may set a domestic contract or a provision in it aside on certain grounds, including non-disclosure of significant assets or debts and lack of understanding. Some terms on children and support can also be overridden.
Does a prenup have to be signed in front of a witness?
Yes. A domestic contract is unenforceable unless it is in writing, signed by the parties and witnessed.
Is independent legal advice required for a valid prenup?
The formal requirements are writing, signatures and a witness, and a lawyer is not one of them. Ontario's government still advises that each partner speak to a different lawyer.
Can a prenup say we waive spousal support?
A contract can deal with support, but a court may set aside a support provision or a waiver in certain situations, such as when it results in unconscionable circumstances.
Sources
- Ontario.ca – Dividing property when a marriage or common law relationship ends — ontario.ca
- Family Law Act, s. 52(1)(a),(b),(d) — Ontario e-Laws
Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.
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