How to Challenge or Set Aside a Prenup in Ontario

If you have separated and believe your prenup is unfair, you may be wondering whether it can be undone. The starting point is that a signed contract is meant to be followed. Ontario law does, however, allow a court to set aside a domestic contract in certain situations.

This article explains the grounds in section 56(4) of the Family Law Act, how courts approach them, what the process looks like and what to gather before you speak with a lawyer. It is general information and every case turns on its own facts.

The starting point: a signed contract must be followed

Once a marriage contract is signed, it must be followed. If the spouses separate and disagree about it, a judge may need to decide. Unfairness alone, or regret about a deal, is not the same thing as a legal ground to undo it.

To be valid in the first place, both spouses must sign the contract in front of a witness, and the witness must also sign. Any later change must also be in writing and witnessed. Checking the signatures and witnessing is a sensible first step.

The three grounds in section 56(4)

Under Family Law Act s. 56(4), a court may, on application, set aside a domestic contract or a provision in it for any of these reasons:

If you felt pressured into signing, how that fits within these grounds depends heavily on the facts, so it is worth confirming with a lawyer.

A two-step process, and all or nothing

Setting aside under s. 56(4) has two steps. First, the applicant must show one of the listed circumstances, which is necessary but not sufficient. Second, the court decides whether to exercise its discretion to set the agreement or provision aside, and fairness can be considered at that stage.

The court can set aside a contract or a provision in its entirety. It does not let the court carve particular assets out of an agreement or amend it. So if you are challenging a property clause, the realistic outcome is that the clause is removed, not rewritten to be fairer.

An Ontario Court of Appeal decision involving a cohabitation agreement, not a prenup, shows how this can play out. The property clauses were set aside because the trial judge found overwhelming evidence that neither party understood the agreement's consequences. In the same case, the spousal support waiver was not set aside, because the trial judge found no particular unfairness from it and there was no finding that the parties misunderstood or did not intend the waiver. Different clauses can have different results.

Time limits and related claims

The Family Law Act sets no limitation period for a s. 56(4) application, so the Limitations Act governs. In one Court of Appeal decision, the majority held that s. 16(1)(a) of that Act applied, so the declaration sought had no limitation period. The equalization claim stays subject to the six-year period, and the support claim has no limitation period.

Do not treat that as a reason to wait. The equalization time limit is six years from the day of separation, or two years from the day the divorce is final, whichever comes first. Delay can also make evidence harder to find.

What a contract cannot control

• Parenting: a contract cannot say who has decision-making responsibility or parenting time for the children. On a Divorce Act application, the court considers only the best interests of the child.
• Child support: a child support order must follow the applicable guidelines, so it is set by the court rather than fixed by the parents' contract.
• Spousal support: the court must consider each spouse's condition, means, needs and circumstances, including any agreement relating to support. Justice Canada's guide says the Miglin test applies on an initial support application in the face of a final agreement, to decide the weight given to the agreement and whether a court may override it.

If a later informal arrangement changed things between you, it may not count. In the cohabitation case above, an informal arrangement did not amend the contract because it was not in writing, signed by the parties and witnessed.

What to do next

• Find the signed contract, including all pages and the witness signature.
• Gather financial statements, tax returns and records of assets and debts from around the date you signed.
• Write down what you were told, what you understood and who gave you advice.
• Keep emails, texts and drafts showing how the contract came about.
• Note the date of separation so you can track time limits.
• Book a meeting with a family lawyer to review the contract and the grounds that might apply.

Frequently asked questions