- Under the Family Law Act, married spouses generally share equally in the growth of each spouse's net worth during the marriage, subject to statutory exclusions — most notably, gifts and…
- A marriage contract can include a clause in which each spouse agrees not to pursue equalization as the Family Law Act would otherwise calculate it, and instead accepts a different…
- Opting out of equalization is broader than most other domestic contract terms, but it still has real limits: - The matrimonial home's possession-related protections.
By default, married spouses in Ontario share the growth in their net worth during the marriage through equalization of net family property under the Family Law Act. That default isn't mandatory in every case — a properly drafted marriage contract can let spouses opt out of it, in whole or in part, and replace it with their own arrangement instead.
Doing this validly takes more than agreeing in principle. Ontario law sets formal requirements for the contract itself, and courts scrutinize equalization waivers more closely than routine contract terms, because a spouse is potentially giving up a substantial financial entitlement. Here's what the process generally involves, and where its limits sit.
What Equalization Normally Does
Under the Family Law Act, married spouses generally share equally in the growth of each spouse's net worth during the marriage, subject to statutory exclusions — most notably, gifts and inheritances received from a third party during the marriage, and property that can be traced directly from them. The matrimonial home receives special treatment on top of that: its value isn't reduced by what it (or a prior home) was worth on the date of marriage, even if one spouse owned it before marrying.
This default scheme applies automatically to every marriage unless the spouses have validly agreed to something different in a domestic contract.
How a Marriage Contract Opts Out
A marriage contract can include a clause in which each spouse agrees not to pursue equalization as the Family Law Act would otherwise calculate it, and instead accepts a different arrangement — for example, each spouse keeping their own property regardless of how much it grows during the marriage, or a specific formula the couple designs themselves. This is sometimes done because one spouse is bringing significantly more assets into the marriage, expects a large inheritance, or owns a business they want to keep entirely separate regardless of how its value changes.
To be enforceable, the contract containing this waiver must meet the Family Law Act's formal requirements: it must be in writing, signed by both spouses, and witnessed. No court approval is needed to sign it.
What a Marriage Contract Generally Can't Waive
Opting out of equalization is broader than most other domestic contract terms, but it still has real limits:
- The matrimonial home's possession-related protections. Ontario law gives both spouses an equal right to possess the matrimonial home, and prevents either spouse from selling, mortgaging, or otherwise encumbering it without the other's consent, a release in a separation agreement, or a court order. A marriage contract signed in advance is not the same mechanism the law contemplates for releasing those specific protections — which means an equalization waiver in a marriage contract doesn't automatically extend to giving up matrimonial home possession rights the same way it can address other property.
- Child support. No domestic contract, however it treats equalization, can eliminate a child's right to support.
- A child's best interests. Equalization is a financial matter between spouses; it has no bearing on how parenting issues get decided.
This is one of the more counterintuitive parts of Ontario family law: a marriage contract can be remarkably effective at reshaping how spouses divide most property, while still leaving certain matrimonial-home-specific protections largely intact regardless of what the contract says.
What Makes an Equalization Waiver More Likely to Hold Up
| Factor | Why it matters |
|---|---|
| Full, honest financial disclosure by both spouses before signing | A waiver is more vulnerable to challenge if a spouse later shows they didn't know what they were actually giving up |
| Independent legal advice for each spouse | Shows each spouse had their own advocate explain the waiver's real effect |
| No pressure or rushed timing (e.g., signing shortly before a wedding with no time to consider it) | Reduces the risk of a later claim that consent wasn't genuine |
| Contract reviewed periodically as circumstances change | An equalization waiver that made sense at signing may look very different after a decade of marriage |
| Clear, unambiguous wording describing exactly what's being waived | Vague language about "keeping things separate" is far weaker than an explicit waiver clause |
A court asked to enforce — or set aside — an equalization waiver years later will generally look at all of these factors together, not just whether the contract technically satisfies the writing, signature, and witness requirements.
Frequently asked questions
Can we waive equalization entirely, or only reduce it?
A marriage contract can generally do either — some couples opt out of equalization completely, while others only exclude specific assets (like a business or an expected inheritance) while leaving the rest of their property subject to the normal default rules.
Does waiving equalization affect spousal support too?
Not automatically. Equalization and spousal support are legally separate issues under the Family Law Act, and a contract addressing one doesn't automatically resolve the other — each typically needs its own clear terms.
If we sign a waiver before marriage and separate decades later, does it still apply?
Generally yes, if it was validly signed and hasn't been formally amended or successfully challenged — but a contract that's decades old, drafted around a very different financial picture, is more likely to face a challenge than one reviewed periodically.
Is a waiver automatically invalid if one spouse didn't have a lawyer?
Not automatically, but it significantly increases the risk that a court could later set the waiver aside, particularly if that spouse can show they didn't understand what they were giving up. Independent legal advice for both spouses is one of the strongest protections available.
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