Nobody plans a wedding by imagining how it might end, which is why the subject of a prenup tends to arrive awkwardly: over dinner, from a worried parent, or from a business partner who just wants to know what happens to the shares. Then the couple has to decide whether the conversation signals distrust or simply good planning.
In Ontario, a prenup is called a marriage contract, and you do not have to sign it before the wedding. Couples who are already married can make one too. It is a tool that fits some families very well and adds little for others, and most of the risk lies in how it is made and not in the idea itself.
Please read this as general information on Ontario law, not as legal advice about your own marriage or finances.
What Ontario Law Assumes If You Sign Nothing
To decide whether you need a contract, begin with what happens without one. If a married couple separates, Ontario’s Family Law Act generally has each spouse calculate their net family property: what they own at separation, minus debts, minus what they brought into the marriage. The spouse with the higher figure usually pays the other half the difference. This is called equalization.
Several details surprise people. Property does not automatically get divided; the value is shared through a payment. Growth in pre-marriage assets is shared, even though the value on the date of marriage is deducted. Gifts and inheritances received during the marriage are generally excluded, but not if they have gone into the matrimonial home. And a home you owned before the wedding usually gets no deduction at all if it is still the family home on separation.
A marriage contract lets a couple replace some or all of this default with rules of their own. Spouses can also write in terms on support, and on what happens on death.
Situations Where a Contract Often Makes Sense
There is no list that fits everybody, but these patterns come up again and again.
You own a business or professional practice. A growing company can become the largest asset on a net family property statement, valued by experts and fought over at length. A contract can exclude the business and its growth from equalization. It can also reassure co-owners that a separation will not drag the company into a dispute. For a small Brampton trucking firm, clinic or family-run shop, this may matter a great deal, because the value is often tied up in equipment and goodwill, not cash.
Family money is involved. Parents who help with a down payment, or who are passing down land or a family property, often want to know that it stays with their child. A contract can address that directly, including the risk created when a gift goes into the matrimonial home.
You already own a home. Someone bringing a paid-down condo into the marriage may be surprised to learn that it can lose its protection once the couple lives there as a family. The contract can specify what happens to that value. This is one of the most common reasons to make one, and it is a poor issue to discover later.
It is a second marriage, or there are children from an earlier relationship. A contract can work alongside a will to protect what you intend to leave to those children, and to clarify how property and support claims are handled on death or separation. Keep in mind that a court can still consider adequate provision for dependants.
One of you has substantial debt. A contract can state who is responsible for a loan or a business guarantee between the two of you. It generally will not bind the lender, but it can clarify what happens between spouses.
One of you will leave work for family reasons. A contract is not only for the wealthier spouse. A spouse planning to step back from a career can negotiate a guaranteed lump sum, a greater share of the home or stronger support terms in exchange for releasing other claims.
When a Contract May Not Be Worth It
If both of you are starting with similar, modest finances, plan to pool everything and are comfortable with the default rules, a contract may offer little. A poorly made contract can even leave you worse off, because you may rely on protection that a court later removes. Legal fees for two lawyers and full disclosure are worth paying only when the contract would actually change something.
A related point: you might want a contract to deal with only one thing. You do not have to rewrite the whole system. A narrow contract protecting one specific asset can be simpler to negotiate and easier to defend.
What a Marriage Contract Cannot Do
Section 52 gives wide scope. Couples can agree on property ownership and division, support, the education and moral training of children, and other matters in settling their affairs. There are still firm limits.
- Parenting. A contract cannot decide decision-making responsibility or parenting time. Those are decided when and if a separation happens, based on the child’s best interests. Courts may disregard any term about a child’s education or moral training where that serves the child’s best interests.
- Child support. A court can disregard a term that is unreasonable having regard to the child support guidelines. A clause saying “neither of us will ever claim child support” offers very little.
- The matrimonial home’s possession rights. A provision that limits a spouse’s rights under Part II of the Act, such as the right to live in the home, is unenforceable. You can agree on who owns the home’s value, but you cannot contract away the possession rights. This is a common drafting mistake.
- Chastity clauses. A term making a right on separation depend on remaining chaste is unenforceable, although a right can depend on remarriage or living with someone new.
- Spousal support waivers in all circumstances. Couples can waive or limit spousal support, but a court can set aside a waiver if it results in unconscionable circumstances, or in some other situations set out in the Act, such as where the person qualifies for support from public funds.
How a Contract Gets Thrown Out
Section 55 sets the bare minimum: the contract must be in writing, signed by both parties and witnessed. Missing one of those can make it unenforceable.
Section 56(4) is where most battles occur. A court may set aside all or part of a domestic contract if a party failed to disclose significant assets, debts or other liabilities that existed when the contract was made, if a party did not understand the nature or consequences of the contract, or otherwise in accordance with the law of contracts. That last category can include situations such as duress and unconscionability.
These rules point directly to the practical steps that protect a contract:
- Full financial disclosure. Each person should exchange a real list of assets, debts and income, with supporting documents and reasonable values. If you own a corporation, say so and explain what it may be worth. Hidden or understated assets are the classic way to lose protection.
- Separate lawyers. One lawyer cannot properly advise both sides. Independent legal advice is not an absolute statutory requirement for marriage contracts, but it is powerful evidence that each person understood what they were signing.
- Time. A contract handed over shortly before the wedding invites claims of pressure. Think about how it looks to a judge if guests had already flown in and the banquet hall in Brampton was paid for. Start months ahead when you can.
- Plain drafting. Each spouse must be able to understand what is being given up. Translation may be needed if one person is not comfortable in English, and a qualified interpreter is usually better than a relative with an interest in the outcome.
- Fair terms. A contract does not have to be equal, but an extremely one-sided one attracts scrutiny. It is also more likely to face challenges down the road if it leaves one spouse with very little after a long marriage.
Having the Conversation
Raising the topic well matters as much as the legal drafting. Some suggestions:
Bring it up early, well before invitations go out. Explain the specific worry you are trying to deal with, such as your parents’ gift, your dental practice or your children from a first marriage. “My lawyer told me to get one” tells your partner very little. It may also help to frame the discussion as something you can both use: what do you each want protected, and what would you each need to feel secure if life changes?
Expect some emotion. In many families, the idea collides with cultural or religious views about marriage, or with pressure from relatives on both sides. Parents may want a contract, or may be offended by one. Remember that the two people signing are the ones who have to live with it, and a contract signed mainly because a parent demanded it may raise questions later about pressure.
Couples sometimes ask whether a religious marriage document, such as a mahr agreement, is the same thing. It may have religious significance, but its legal effect in Ontario is a separate question that depends on what it says and how it was made. If you have one, or plan to have one, show it to your lawyer so it can be dealt with deliberately and does not conflict with your contract. Ontario law also has rules about religious barriers to remarriage, which your lawyer can explain if they apply.
Timing, Changes and Reviews
A contract can be made before the wedding, taking effect upon marriage, or at any time during it. A contract signed by a couple who are living together also matters: a cohabitation agreement automatically becomes a marriage contract if the two later marry.
A contract is not necessarily permanent. An agreement to amend or rescind must meet the same formalities: written, signed, witnessed. Consider reviewing it after a large life event, such as the birth of a child, selling or buying a business, relocating, or a significant change in income. Courts look at whether contracts were fair and properly made, and a contract that has been kept current is easier to explain than one that nobody has looked at in fifteen years.
A marriage contract should also be coordinated with a will, beneficiary designations and, for business owners, shareholder agreements. A contract that says one thing while the shareholder agreement says another creates trouble. Ask your lawyer to read the documents together.
What to Bring to a First Meeting
A first discussion will go much further if you bring a rough net worth statement, your most recent tax return, details of any property you own, shares and corporate documents, any promised or expected gifts or inheritances and a list of debts. If a wedding date is booked, say so at the start. It affects how quickly the work needs to happen and how much time each person has for a meaningful review.
A marriage contract does not predict that a marriage will fail. It is a decision about what you want to happen if life goes differently than planned, made while you are still on good terms and able to listen to each other. If you want to find out whether one would be useful for your family, our family law team can talk it through, and you can reach out here to book a consultation.