Prenuptial Agreement in Ontario: Is It Legally Enforceable?

If you are about to sign a prenuptial agreement, or already have one, you may wonder whether it is worth the paper it is written on. The short answer is that Ontario law gives these agreements real force, but only if they are made properly and only to the extent the law allows.

This article explains what the law calls a prenup, what makes it valid, the usual reasons a court sets one aside, and the parts a court can override regardless of what you signed.

What Ontario law calls a prenup

The Family Law Act does not use the words prenup or prenuptial agreement. Those are informal names, and the Act speaks of a marriage contract. A marriage contract is one type of domestic contract, a category that also includes separation agreements and cohabitation agreements.

People who are married to each other, or who intend to marry, may make a marriage contract. In it they can agree on their rights and obligations during the marriage, on separation, on annulment or dissolution, or on death. Despite the name, you can also make one after the wedding, because the Act covers people who are already married.

What makes a prenup valid

A domestic contract, and any later agreement to change or cancel it, is unenforceable unless it is in writing, signed by the parties and witnessed. Ontario government guidance says both spouses sign in front of a witness, and the witness signs too. Once signed, the couple must follow it.

There are special rules for people who cannot sign for themselves in the usual way:

• A minor can enter a domestic contract 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 the contract.
• In other cases of mental incapacity, the Public Guardian and Trustee has power to act.

A contract made outside Ontario has its formalities and validity governed by its proper law, meaning the law that governs the contract. Even so, the setting-aside rules in section 56 and the support override in section 33(4) still apply in Ontario.

Common reasons a court sets a prenup aside

On application, a court may set aside a domestic contract, or a provision in it, on three grounds. A contract clause cannot take that power away, because these rules apply despite any agreement to the contrary.

The Act does not address signing close to the wedding or feeling pressured by name. Those arguments are made under the contract law ground, and a judge decides them on the facts of each case. Whether a particular agreement would hold up depends on its circumstances, which a lawyer can help you assess.

Parts a court can override even if the prenup is valid

• Matrimonial home: any term that tries to limit a spouse's rights under Part II, which includes the equal right to possession of the home, is unenforceable. Both spouses have that equal right whoever owns the home. If only one spouse has an interest in the home, though, the other spouse's right of possession is personal as against the owner and ends when they stop being spouses, unless a separation agreement or court order says otherwise.
• Children: a court may disregard a term about a child's education, moral training, decision-making responsibility or parenting time if doing so is in the child's best interests. A marriage contract also cannot decide decision-making responsibility or parenting time in the first place.
• Child support: a court may disregard a term 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 it involves a dependant who qualifies for support out of public money, or if support under the contract is in default.
• Chastity clauses: a term that ends rights on separation if a party is not chaste is unenforceable.

For married people who divorce, the federal Divorce Act treats an agreement about support as one factor the court weighs, not a bar to support.

What to do next

• Check that your agreement is in writing, signed by both of you and witnessed.
• List your assets and debts as they stood when you signed, and compare them with what was disclosed.
• Note any terms about the home, children or support, since those are the likeliest to be questioned.
• Keep copies of drafts, emails and financial information exchanged before signing.
• Speak with a family lawyer before relying on, or challenging, the agreement.

Frequently asked questions