Prenuptial & Postnuptial
Agreements in Ontario

What Is a Prenuptial Agreement in Ontario?

In Ontario, a prenuptial agreement is legally called a marriage contract and is governed by Part IV of the Domestic Contracts Act. It is a written agreement signed by two people before they marry, setting out how their finances, property, and support obligations will be handled — both during the marriage and if the marriage ends.

Marriage contracts are not just for the wealthy. They are practical tools for anyone entering a marriage with pre-existing assets, a business interest, property, an inheritance, or prior financial obligations such as support from a previous relationship.

What Can a Prenuptial Agreement Cover?

• Property ownership and division — protecting assets you owned before marriage, or defining how jointly acquired property will be divided
• Exclusion of specific assets — keeping an inheritance, a business, or an investment account out of the equalization calculation on separation
• Spousal support — agreeing in advance on whether support will be paid, in what amount, and for how long — or waiving support entitlement entirely
• Debts and liabilities — clarifying which debts belong to whom and who is responsible for them if the marriage ends
• Estate rights — addressing certain entitlements that may arise on death

Note that a marriage contract cannot limit or set aside child support obligations — those are always determined in the best interests of the child at the time of separation.

"A prenuptial agreement is not planning for divorce. It is planning for life — and giving yourselves a clear framework when clarity matters most."

Is a Prenuptial Agreement Enforceable in Ontario?

Yes — if properly drafted and executed. Under the Domestic Contracts Act, a marriage contract is enforceable if it is in writing, signed by both parties in the presence of a witness, and entered into without fraud, duress, or undue influence.

Courts can set aside all or part of a marriage contract if a party failed to disclose significant assets, if a party did not understand the nature of the agreement, or if the terms would be unconscionable to enforce given the circumstances at the time of separation.

The most important protection against a future challenge is independent legal advice (ILA). Both parties should have their own independent lawyer review and advise on the agreement. Solvine Law provides ILA and full contract drafting services.

The Process at Solvine Law

• Free 15-minute consultation to discuss your situation and confirm scope
• Financial disclosure from both parties (required for a valid contract)
• Custom drafting of the marriage contract based on your specific circumstances
• Review and execution guidance
• Execution with proper witnessing and independent legal advice

Timing matters. A prenuptial agreement should be completed well before the wedding date — ideally at least 60 days before — so neither party can later claim it was signed under pressure.

What Is a Postnuptial Agreement in Ontario?

A postnuptial agreement (also a marriage contract under the Domestic Contracts Act) is signed after marriage. It serves the same purpose as a prenuptial agreement but addresses circumstances that have changed since the wedding — a new business, an inheritance, a change in career, or a shift in financial position.

Postnuptial agreements are also used when a couple wants to redefine the financial terms of their marriage after a period of difficulty — as a way of putting the relationship on clearer footing going forward.

When a Postnuptial Agreement Makes Sense

• You started a business after getting married and want to protect it from equalization
• You received or expect to receive a significant inheritance
• One spouse has taken on significant debt that the other does not want to share responsibility for
• You and your spouse want to formally update or replace a prenuptial agreement that no longer reflects your situation
• You want to define spousal support expectations before circumstances change further

Enforceability and Requirements

A postnuptial agreement is held to the same legal standard as a prenuptial agreement. It must be in writing, signed and witnessed, and entered into freely, with full financial disclosure from both parties. Courts will scrutinize agreements signed during periods of marital difficulty more carefully, which makes clear drafting and independent legal advice even more important.

The Process at Solvine Law

• Free 15-minute consultation to understand your current situation and what you want to address
• Full financial disclosure from both parties
• Custom drafting tailored to your circumstances
• Review and execution guidance
• Independent legal advice and proper execution

All services are delivered virtually. You do not need to come to an office — everything can be completed online, anywhere in Ontario.