Is a prenuptial agreement enforceable in Ontario?
Yes, but only if strict requirements are met. Both parties must sign voluntarily, each must receive independent legal advice from their own lawyer, both must fully disclose their financial situation, and the terms must be fair and reasonable. Agreements signed without these protections are at serious risk of being set aside.
Key Points
Yes — a properly executed marriage contract (the Ontario term for a prenuptial agreement) is legally binding.
However, courts can set aside a marriage contract if the conditions for valid execution were not met: both parties must have received independent legal advice, full financial disclosure must have been made, and neither party must have signed under duress.
Detailed Answer
Ontario Family Law Act permits spouses to enter into a marriage contract before or during marriage that governs how their property and support will be handled on separation. A marriage contract can exclude assets from equalization, modify support entitlements, and address specific property.
For a marriage contract to be enforceable, several conditions must be satisfied. First, each party must have received independent legal advice (ILA) from their own lawyer — not a shared lawyer. Second, both parties must have made full financial disclosure before signing. Third, the agreement must have been signed voluntarily, without duress, undue influence, or oppressive time pressure. Fourth, a witness must be present at signing.
Courts scrutinize marriage contracts carefully. A contract signed days before the wedding, with no time for proper review, is at elevated risk of challenge. A contract where one party did not truly understand what they were signing — perhaps due to a language barrier — may also be vulnerable.
One area of particular difficulty is the matrimonial home. Even if a marriage contract purports to exclude the matrimonial home from equalization, courts have sometimes declined to enforce such provisions.
If you are considering a marriage contract — whether before marriage or during — contact Miao He at 647-930-6688 for advice on how to make it as robust as possible.
Still have questions?
Miao He · Mandarin & English · 30 min consultation $220 + HST · Markham · All of Ontario
