Can a Prenup or Marriage Contract Waive Spousal Support in Ontario?

Yes, but with limits. A marriage contract, which is the Family Law Act's name for a prenup, can deal with support obligations, and a domestic contract generally prevails over the Act where both cover the same matter. But a court can set aside a support waiver or limit if it results in unconscionable circumstances, if the waiver is by or for a dependant who qualifies for support out of public money, or if support under the contract is in default when the application is made.

The whole contract can be set aside if a party failed to disclose significant assets or debts, did not understand the contract, or if general contract law applies, such as duress. No clause can remove those powers. For divorcing spouses, the federal Divorce Act treats an agreement as one factor the court weighs, not a bar to support. To be enforceable, the contract must be in writing, signed and witnessed, and couples who are already married can make one too.

Ontario's government advises each partner to see a different lawyer and exchange financial information before signing, though the formal requirements do not include a lawyer. Whether a particular waiver would hold up depends on the facts, so a lawyer can confirm.