Can a Prenuptial Agreement Be Overturned? What Makes It Invalid? 

Only 5 to 10% of Canadians have a prenuptial agreement, but that number is rising, especially among millennials. Over 52% of millennials now want a prenup before marriage, reflecting a shift in how younger generations approach financial security. 

With people marrying later in life, many enter relationships with established careers, properties, and savings they want to protect. But while prenups are designed to offer clarity, they aren’t always ironclad.

Ontario courts will overturn a prenup for a number of reasons, here’s what you need to know.

When Can a Prenup Be Overturned in Ontario?

Prenuptial agreements in Ontario fall under the Family Law Act, but courts will not automatically enforce them if they seem unjust or were created under questionable circumstances. Judges examine how the agreement was made, whether both parties understood it, and whether enforcing it would be fair.

Here are the main reasons: 

Lack of Full Financial Disclosure

If one spouse hides assets, debts, or income, the other spouse may argue that they agreed to the contract under false pretenses. Ontario courts take financial dishonesty seriously and invalidate the whole prenup. You must disclose all your assets, properties, and salary before signing the agreement. 

Duress or Coercion

If one spouse was pressured, threatened, or emotionally manipulated into signing, you can challenge it at the time of separation. Duress can range from forcing someone to sign right before the wedding to threatening to cancel the wedding or withdraw financial support or discouraging them to get legal counsel. 

Unfair or Unconscionable Terms

If a contract heavily favors one spouse to the point of being unreasonable, a judge will refuse to honour it. Ontario courts assess fairness based on the circumstances at the time of signing and how the prenup will affect both spouses. 

Some examples include:

• One spouse gets all assets, while the other gets nothing
• One spouse waives all rights to spousal support, even if they left a career to raise children
• One spouse’s financial obligations are extreme compared to the other’s

Lack of Independent Legal Advice

Both spouses must have their own lawyers review the contract before signing. It’s their chance to ask questions, clear doubts, and amend any clauses. Courts may invalidate the prenup entirely or adjust certain clauses if it seems that one party did not have a proper chance to negotiate.

Errors in the Contract

Legal mistakes are unacceptable by court. If the judge feels the agreement is written vaguely, includes contradictory clauses, and doesn’t meet Ontario’s family law requirements, they can invalidate it. 

What a Prenup Cannot Override in Ontario

Whether mentioned in the agreement or not, it cannot override child support and parenting time agreement. Ontario law requires that decisions about children be made in their best interests at the time of separation. 

It also limits clauses about the matrimonial home, as both spouses have equal rights to the property regardless of the agreement. 

If you have concerns about your prenup, speak with a family lawyer to understand your rights and legal options. Book a consultation with Noori Law today.