Why prenuptial agreements matter in Canada
A prenuptial agreement (prenup) is a written contract, signed before or during a marriage, that sets out how property, debts and spousal support will be handled if the relationship ends. Common-law couples sign the equivalent, a cohabitation agreement. Family law is provincial, so the name, the rules and what a court will enforce depend on where you live. This page is part of our guide to life stages and life events.
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 the different names, they do the same job: setting how property and support are handled on separation or death.
What you can include in a prenup
Commonly included
- Division of property: who keeps the assets each partner brought into the marriage, and how assets bought together are split.
- Business ownership: whether a business started before or during the marriage, and its growth, is shared.
- Spousal support: whether support will be paid, how much and for how long. Courts can still review a support waiver that leaves a spouse in hardship; how support is estimated without an agreement is explained in the spousal support calculator.
- Debts: who is responsible for debts brought into the marriage.
- Inheritances: keeping family inheritances separate.
- Investment accounts: how RRSPs, TFSAs and non-registered accounts are handled.
What a prenup can’t settle
- Parenting arrangements: decision-making and parenting time are decided on the best interests of the child at the time of separation.
- Child support: it follows the Federal Child Support Guidelines (see the child support calculator), and a court isn’t bound by a clause that sets it lower.
- Unconscionable terms: a clause that leaves one spouse destitute can be set aside.
What a prenup costs
Each partner needs independent legal advice (ILA), so a prenup means two lawyers’ fees. The cost depends mostly on how much there is to disclose and negotiate: a couple with few assets and simple terms pays far less than one with a business, rental properties, foreign assets or children from earlier relationships. Lawyers charge either a flat fee for a standard agreement or hourly for negotiated terms; typical rates are covered in how much a lawyer costs in Canada. Skipping independent legal advice is one of the most common reasons an agreement is challenged in court.
Province-by-province enforceability rules
Ontario
Under the Family Law Act, a marriage contract can address property division and spousal support. The matrimonial home has special status: both spouses have an equal right to possession regardless of title, and a contract can’t take that right away, 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 excluded property (brought into the relationship) from family property (acquired during it). A marriage agreement can override the default rules, including keeping the growth of excluded property separate. Courts can set aside an agreement that 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 lets prenuptial agreements set how property is divided. Independent legal advice for each partner and full financial disclosure are what courts look for when an agreement is challenged.
Quebec
Quebec has a civil law system. Marriage contracts must be notarized to be valid. Quebec’s mandatory family patrimony rules (the family residence, furniture, vehicles and pension plans earned during the marriage) are split equally regardless of a marriage contract, but spouses can contract out of the matrimonial regime (for example, the 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 for both parties | Each person understands their rights and obligations |
| Full financial disclosure | Both parties know what they’re agreeing to |
| Signed voluntarily | Signing under pressure, or hours before the wedding, invites a challenge |
| Fair and reasonable terms | Unconscionable terms can be struck down |
| Witnessed | Most provinces require a witness for each signature |
When couples consider a prenup
A prenup isn’t only for the wealthy. Situations where couples often sign one:
- A business: without an agreement, a spouse may be entitled to a share of the business’s growth during the marriage.
- Significant pre-marriage assets: real estate, investments or savings either partner wants to keep separate.
- An inheritance received or expected: inheritances can become shared property once mixed with family assets.
- A previous marriage: protecting assets for children from an earlier relationship.
- Significant debt: making clear that pre-existing debt stays with the partner who owes it.
- Very different incomes: setting expectations around spousal support.
Prenup vs. cohabitation agreement
| Feature | Prenuptial agreement | Cohabitation agreement |
|---|---|---|
| When signed | Before or during marriage | While living together, unmarried |
| Who it’s for | Engaged or married couples | Common-law partners |
| Property division | Covered | Covered |
| Spousal support | Covered | Covered (may be harder to enforce in some provinces) |
| Becomes a marriage contract | Not applicable | Yes, in most provinces, if the couple marries |
Common-law couples have different property rights from married couples in most provinces, which is why a cohabitation agreement matters more for them; the rest of the money side of living together is in common-law relationship finances.
How to get a prenup: step by step
- Start the conversation early. Months before the wedding, so there’s no appearance of pressure.
- List assets and debts. Full financial disclosure is required.
- Agree on the general terms together before involving lawyers.
- Hire separate lawyers, one for each partner.
- Draft and negotiate. One partner’s lawyer usually writes the first draft.
- Review and revise until both partners are satisfied.
- Sign in front of witnesses.
- Store the originals with the lawyers, and keep a copy.
Common mistakes that weaken a prenup
- Last-minute signing: presenting it days before the wedding suggests duress.
- Sharing a lawyer: each party needs independent advice.
- Hiding assets: incomplete disclosure is grounds for setting the agreement aside.
- Child-related terms: custody and child support clauses don’t bind a court.
- Never updating it: an agreement written decades earlier may not fit the couple’s life now.
Updating or revoking a prenup
A prenup can be amended or revoked at any time if both partners agree in writing. Common reasons to update one are the birth of a child, a big change in income or assets, one spouse starting a business, buying a new home, or moving to a province with different family law rules.
Other money steps around a wedding are in the getting married financial checklist, and what happens if the marriage ends is in the divorce and separation financial checklist.