What an Ontario marriage contract is for
When an Ontario marriage ends, by separation or by death, Part I of the Family Law Act equalizes the spouses' net family property. Each spouse totals the value of what they own at the end, subtracts what they brought into the marriage (except the matrimonial home), and the spouse with the larger result pays the other half the difference. That formula catches things couples often do not expect: the full value of a house one spouse owned before the wedding if it became the matrimonial home, the growth of a business started years earlier, and an inheritance used to pay down the mortgage. On death, the survivor can choose equalization instead of what the will leaves them.
A marriage contract lets the couple decide which property sits outside that formula. This template defines excluded property to include its growth and anything traced from it, protects gifts and inheritances regardless of what the donor said, gives three options for the matrimonial home and covers a family cottage, a business and pensions. It sets spousal support terms, deals with equalization on death and the 2022 changes to Ontario wills law, and includes disclosure schedules, legal advice certificates, an equalization illustration and an after-signing checklist.
When to sign one
The most common reasons are owning a business or shares, owning a home before the wedding, expecting a significant inheritance or a family cottage, having children from a previous relationship, or a large difference in wealth. It can be signed before the wedding, which is best, or at any time during the marriage.
Allow time. Each spouse needs complete disclosure from the other, their own lawyer, and room to negotiate. A contract signed in the last week before the wedding, or presented by one spouse's family lawyer to a spouse with no advice, is the kind courts most often set aside.
What's inside
The full list of sections and fields in this template, in the order they appear.
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Background and legal effect
- Parties
- Wedding date
- Children
- Effective on marriage
- Replaces cohabitation agreement
- Effect of Part I
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Excluded property
- Listed property
- Gifts and inheritances
- Growth in value
- Tracing
- Business or cottage
- Related debts
- Commingling rule
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Equalization of the rest
- Equalize everything except excluded property
- No equalization
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Business, home and cottage
- Business and its growth
- Salary from the business
- Spousal consents
- Matrimonial home options
- Possession cannot be limited
- Cottage
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Pensions and support
- Pensions and registered plans
- Support under law
- Limited by length of marriage
- Lump sum
- Mutual release
- Court override
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Children and death
- Children's best interests
- Release of equalization election on death
- Minimum provision
- 2022 will rules
- Dependants' support
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Disclosure, advice and general
- Financial disclosure
- Independent legal advice
- Timing before the wedding
- Amendment
- Reconciliation
- Governing law
- Witnessed signatures
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Schedules A to E
- Disclosure of each spouse
- Legal advice certificates
- Equalization illustration
- After-signing checklist
Preview pages
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Page 1 -
Page 2 -
Page 3
How to complete the contract
- Exchange disclosure. Each spouse fills in their schedule with values and documents, including expected inheritances and business valuations.
- Decide what is excluded. List the property, and decide whether its growth is excluded too.
- Choose how the rest is shared. Equalize everything else, or opt out entirely.
- Deal with the business. Name it, exclude its growth, and set how salary is treated.
- Choose the home and cottage options. Shared, down payment protected, or excluded.
- Decide pensions and spousal support.
- Set death terms. Release the equalization election, and provide for the survivor by will or insurance if you wish.
- Get independent legal advice. Each lawyer signs a certificate; complete the illustration in Schedule D.
- Sign in front of witnesses. Then update wills, beneficiary designations and spousal consents.
Example: a business and an inheritance
Fictional couple Ravi Menon and Claire Dubois marry in Guelph on September 12, 2026. Ravi owns 100% of a software consultancy worth $600,000; Claire expects to inherit her parents' Muskoka cottage.
Excluded Property: Ravi's shares and all their growth; Claire's future inheritance, including the cottage, even if used by the family. Matrimonial home: bought jointly in 2027 for $950,000; Claire contributed a $150,000 down payment from an earlier gift. Option: owner's down payment protected, so on separation Claire receives $150,000 first and the rest of the equity is shared. Spousal support: limited by length of marriage, with no claim if they separate within five years.
If they separate in 2036 and Ravi's company is then worth $2.4 million, the $1.8 million of growth is not shared. Without the contract, Claire could have claimed about $900,000 of it through equalization.
Ontario rules to know
- Marriage contracts (Family Law Act section 52). Cover property, support, children's education and moral training, and other matters; cannot limit possession of the matrimonial home.
- Formalities (section 55(1)). In writing, signed by both and witnessed.
- Equalization (sections 4 and 5). Half the difference in net family property; the matrimonial home cannot be deducted as date-of-marriage property.
- Excluded property (section 4(2)). Third-party gifts and inheritances, and property excluded by a domestic contract.
- Death (sections 5(2) and 6). The survivor may elect equalization; a contract can release that right.
- Setting aside (section 56(4)). Non-disclosure of significant assets or debts, failure to understand, or other contract grounds.
- Wills (Succession Law Reform Act, 2022). Marriage no longer revokes a will; separated spouses lose intestate rights.
Why Ontario marriage contracts fail
Ontario courts set aside marriage contracts most often for missing disclosure: a business valued at a fraction of its worth, a pension left out, or an expected inheritance not mentioned. Others fail because one spouse had no independent lawyer, or signed under pressure just before the wedding. Some survive but protect less than intended: they exclude a business's date-of-marriage value but not its growth, or protect an inheritance that was later put into the matrimonial home without saying so. The disclosure schedules, legal advice certificates, growth and commingling clauses, and home options in this contract address each of these.
Frequently asked questions
Is a prenup called a marriage contract in Ontario?
Yes. The Family Law Act uses the term marriage contract for an agreement between spouses, or people about to marry, about property, support and other matters. It must be in writing, signed by both parties and witnessed, and can be signed before or after the wedding.
What can an Ontario marriage contract not do?
It cannot limit either spouse's right to live in the matrimonial home, cannot bind a court on child support or parenting arrangements, and a spousal support waiver can be overridden if it leads to unconscionable results. Everything else about property and support can generally be agreed.
Does an inheritance stay separate in an Ontario marriage?
Usually, if it can be traced and is not put into the matrimonial home. If an inheritance is used to pay down the mortgage on the matrimonial home, it loses its exclusion and is shared. A marriage contract can protect it even then.
How does a marriage contract protect a business in Ontario?
By listing the business, or the shares, as excluded property together with all of its growth during the marriage, so its value is left out of the owner's net family property. Without that, the growth in value of the business during the marriage is shared through equalization.
Does getting married revoke my will in Ontario?
Not since January 1, 2022. Marriage no longer revokes an existing will in Ontario, so couples should update their wills after marrying and signing a marriage contract to match its terms.
