Why Prenuptial Agreements Matter in Canada
A prenuptial agreement (prenup) is a legally binding contract signed before marriage that outlines how assets, debts, and spousal support will be handled if the relationship ends. While the topic can feel uncomfortable, a prenup protects both partners and removes uncertainty during an already stressful time.
In Canada, family law is provincial, so the rules, terminology, and enforceability standards vary depending on where you live.
What a Prenup Is Called Across Canada
| Province / Territory | Legal Term | Governing Legislation |
|---|---|---|
| Ontario | Marriage contract | Family Law Act |
| British Columbia | Marriage agreement | Family Law Act |
| Alberta | Prenuptial agreement | Family Property Act |
| Quebec | Marriage contract | Civil Code of Québec |
| Manitoba | Domestic contract | Family Property Act |
| Saskatchewan | Interspousal contract | Family Property Act |
| Nova Scotia | Domestic contract | Matrimonial Property Act |
| New Brunswick | Domestic contract | Marital Property Act |
Despite different names, they serve the same core purpose: defining how property and support are handled on separation or death.
What You Can Include in a Prenup
Commonly included
- Division of property — Who keeps what assets brought into the marriage and how jointly acquired assets are split
- Business ownership — Protection for a business started before or during the marriage
- Spousal support — Whether support will be paid, how much, and for how long
- Debt allocation — Who is responsible for debts brought into the marriage
- Inheritance protection — Keeping family inheritances separate
- Investment accounts — How RRSP, TFSA, and non-registered accounts are handled
Cannot include
- Child custody or access — Courts always decide based on the best interests of the child
- Child support — Determined by the Federal Child Support Guidelines, not private agreements
- Anything illegal or unconscionable — A clause that leaves one spouse destitute will be struck down
Cost of a Prenup in Canada (2026)
| Complexity | Estimated Cost | Typical Scenario |
|---|---|---|
| Simple | $2,500–$5,000 | Few assets, no business, straightforward terms |
| Moderate | $5,000–$10,000 | One business or rental property, moderate assets |
| Complex | $10,000–$25,000+ | Multiple businesses, international assets, blended families |
Both parties need independent legal advice (ILA). Each partner hires their own lawyer, so budget for two sets of legal fees. Skipping ILA is the single biggest reason prenups get thrown out in court.
Province-by-Province Enforceability Rules
Ontario
Under the Family Law Act, a marriage contract can address property division and spousal support. However, the matrimonial home has special status — both spouses have an equal right to possession regardless of title. A prenup cannot fully waive this right, though it can address the home’s value in the equalization calculation.
Ontario courts may set aside a contract if:
- A party did not receive independent legal advice
- One party did not understand the nature or consequences of the contract
- There was no financial disclosure
- The contract is unconscionable
British Columbia
BC’s Family Law Act distinguishes between excluded property (brought into the relationship) and family property (acquired during). A marriage agreement can override default rules, including keeping excluded property growth separate.
Courts can set aside an agreement if it is “significantly unfair” considering the length of the relationship, whether a party was misled, or whether the agreement is unconscionable.
Alberta
Alberta’s Family Property Act allows prenuptial agreements to determine how property is divided. Both independent legal advice and full financial disclosure are strongly recommended to ensure enforceability.
Quebec
Quebec operates under a civil law system. Marriage contracts must be notarized to be valid. Quebec also has mandatory family patrimony rules — the family residence, furniture, vehicles, and pension plans earned during marriage are split 50/50 regardless of a marriage contract. However, spouses can contract out of the matrimonial regime (e.g., partnership of acquests) to keep other property separate.
Requirements for an Enforceable Prenup
| Requirement | Why It Matters |
|---|---|
| Written and signed | Oral agreements are not enforceable |
| Independent legal advice (both parties) | Each person understands their rights and obligations |
| Full financial disclosure | Both parties know what they’re agreeing to |
| Voluntary execution (no duress) | Signing under pressure or hours before the wedding raises red flags |
| Fair and reasonable terms | Unconscionable terms will be struck down |
| Witnessed | Most provinces require at least one witness per signature |
When You Should Consider a Prenup
A prenup isn’t just for the wealthy. Consider one if:
- You own a business — Without a prenup, your spouse may be entitled to a share of business growth during marriage
- You have significant pre-marriage assets — Real estate, investments, or savings you want to keep separate
- You’re receiving or expecting an inheritance — Inheritances can become family property if commingled
- You’ve been married before — Protecting assets for children from a previous relationship
- One partner has significant debt — Clarifying that pre-existing debt stays with the debtor
- You and your partner have very different incomes — Defining expectations around spousal support
Prenup vs. Cohabitation Agreement
| Feature | Prenuptial Agreement | Cohabitation Agreement |
|---|---|---|
| When signed | Before marriage | While living together (unmarried) |
| Who it’s for | Engaged or soon-to-be-married couples | Common-law partners |
| Property division | Covered | Covered |
| Spousal support | Covered | Covered (may be harder to enforce in some provinces) |
| Can convert to marriage contract | N/A | Yes, in most provinces |
If you’re in a common-law relationship, a cohabitation agreement serves a similar purpose. In many provinces, it automatically becomes a marriage contract if you later marry.
How to Get a Prenup: Step by Step
- Start the conversation early — Ideally 3–6 months before the wedding to avoid any appearance of duress
- Each partner lists assets and debts — Full financial disclosure is mandatory
- Discuss goals together — Agree on the general terms before involving lawyers
- Hire separate lawyers — Each party gets independent legal advice
- Draft and negotiate — The initiating party’s lawyer typically writes the first draft
- Review and revise — Both lawyers negotiate terms until both parties are satisfied
- Sign with witnesses — Execute the final agreement in the presence of witnesses
- Store safely — Keep originals with your lawyers and a copy at home
Common Mistakes That Invalidate a Prenup
- Last-minute signing — Presenting a prenup days before the wedding suggests duress
- Sharing a lawyer — Both parties must have independent legal counsel
- Hiding assets — Incomplete financial disclosure is grounds for setting aside the agreement
- Including child-related terms — Custody and child support clauses will be ignored by courts
- Never updating it — A prenup written 20 years ago may not reflect current circumstances
Updating or Revoking a Prenup
Prenups can be amended or revoked at any time, as long as both parties agree in writing. Common triggers for updating include:
- Birth of children
- A major change in income or assets
- One spouse starting a business
- Purchasing a new matrimonial home
- Moving to a different province (which may have different family law rules)