Prenuptial agreements, why more couples are getting them and what they cover

The stigma around prenuptial agreements is fading, and it should be. A prenup is a financial planning document. It defines what each person brings into the marriage, how things will be treated if the marriage ends, and what each party's expectations are around money. Having that conversation before you're married is, by most measures, healthier than having it during a divorce.

Raising it can feel awkward, even unromantic, and many people put it off until it is too late to do properly. It helps to treat it as part of planning a shared life, the same way you would talk about where to live or whether to have children.

The couples who resist prenups most strongly are often the ones who need them most: couples with significant asset asymmetry, business ownership, or children from previous relationships. Those situations create exactly the kind of complexity that benefits from being addressed in writing before emotions are running in the opposite direction.

Who should consider a prenuptial agreement?

A prenup is worth considering seriously if any of these apply:

• You're entering the marriage with significant assets, a property, an investment portfolio, a business, or an inheritance.
• You own all or part of a business, or expect to during the marriage. Business valuation in divorce is truly complex and expensive. A prenup that pre-defines how business interests will be treated removes a major source of litigation. Our guide to dividing a business at separation shows what is at stake.
• You have children from a previous relationship. A prenup can specify which assets are intended for those children and protect them from being divided in a future divorce.
• There's a significant income disparity. Not because spousal support should be avoided, but because both parties benefit from knowing what the expectations are.
• You expect to receive a significant inheritance. Without a prenup, inherited property can become shared property in some circumstances, particularly if it's mixed with marital assets.
• You've been through a difficult divorce before and want more certainty this time.

This is not an exhaustive list. The right question is: are there financial realities in your situation that would be much easier to address now than later? If the answer is yes, consider a prenup. If you are moving in together without marrying, the equivalent document is a cohabitation agreement.

What does a prenup cover?

Prenuptial agreements are fundamentally agreements about property. They define:

• What stays separate. Assets each person brings into the marriage can be defined as remaining separate property, not subject to division if the marriage ends. This includes property owned before marriage, inheritances, and gifts received by one spouse.
• What becomes shared. You can specify which assets, if any, will be treated as marital property even if they're currently held by one party. Some couples choose to share the matrimonial home regardless of who bought it; others don't.
• Spousal support. A prenup can address whether support will be paid, in what amount and for how long, and it can try to waive support entirely. Support terms are the most vulnerable part of any prenup. In Canada, courts can override a support waiver that produces an unconscionable result when the marriage ends; in Ontario that power is in section 33(4) of the Family Law Act. In the US, rules vary by state; California, for example, will not enforce a support waiver unless the person giving up support had their own lawyer.
• What happens to the family home. Whether one party has the right to buy out the other, whether the home must be sold, and how the proceeds are divided.
• Debt. Pre-existing debt can be defined as each party's sole responsibility.
• Death. Many prenups also deal with what each spouse can claim from the other's estate, which matters most in second marriages and blended families.

What can a prenup not do?

This is equally important. A prenuptial agreement cannot:

• Set child support or parenting terms. Courts always have jurisdiction over children, and any terms in a prenup purporting to fix future child support or custody arrangements will not be enforced. The best interests of the children at the time of separation is the standard, and that can't be determined in advance.
• Include terms that are grossly unconscionable. An agreement that would leave one spouse destitute, particularly after a long marriage where one party gave up a career, may be set aside in whole or in part by a court.
• Contain non-financial terms. You cannot enforce lifestyle clauses (who does the housework, where you spend holidays, how often you have sex). These are not legally binding.
• Be based on incomplete disclosure. If one party hid significant assets or debts when the agreement was negotiated, the agreement can be challenged on that basis.
• Override certain home rights in Ontario. An Ontario marriage contract cannot limit a spouse's right to possession of the matrimonial home.

What makes a prenup enforceable?

A prenup that isn't enforceable is just a piece of paper. The requirements vary somewhat by jurisdiction, but the core elements are consistent:

In Canada

Marriage contracts are governed by provincial law, so the details depend on where you live.

Ontario. Under Part IV of the Family Law Act, a marriage contract must be in writing, signed by both of you and witnessed. A court can set it aside if one of you failed to disclose significant assets or debts, if one of you did not understand the nature or consequences of the contract, or on ordinary contract grounds such as duress, undue influence or unconscionability. Independent legal advice is not a strict statutory requirement in Ontario, but it is the strongest protection a contract can have, and courts look closely at agreements signed without it.

British Columbia. A court can set aside or replace the property terms of an agreement that is significantly unfair, looking at factors such as how long ago it was made and whether the spouses intended it to give certainty.

Quebec. A marriage contract must be signed before a notary. Spouses also cannot opt out of the family patrimony rules in advance, which cover the family residences, household furniture, family vehicles and pension and Quebec Pension Plan credits earned during the marriage.

Across Canada, courts can step in where an agreement was unfair when signed or has become unconscionable in circumstances nobody planned for, particularly on support. The test is demanding: an unequal outcome on its own is not enough.

In the US

About half the states, plus the District of Columbia, have adopted a version of the Uniform Premarital Agreement Act (UPAA) or the newer Uniform Premarital and Marital Agreements Act (UPMAA). The others rely on their own statutes and case law. The common themes are similar to Canada's: a written agreement, fair financial disclosure, voluntary signing, and no unconscionable terms.

State law varies, and some states are stricter. In California, an agreement is not treated as voluntary unless, among other things, each party had independent counsel or expressly waived it in a separate document, and at least seven calendar days passed between being presented with the final agreement and signing it. A party without a lawyer must also have been fully informed of the terms and the rights being given up, in writing and in a language they understand. Work with a lawyer who knows your state's rules; our family law by province and state hub is a good place to start.

Timing matters more than people realise

Agreements signed very close to the wedding date are much more vulnerable to challenge. The argument is that one party was under social and emotional pressure not to rock the boat right before the wedding, which can be argued to constitute duress, or at minimum calls into question whether the signing was truly voluntary.

The earlier the better. Ideally, start the conversation months before the wedding, negotiate in full, sign well in advance, and treat the agreement as separate from the wedding planning entirely. Springing a prenup on a partner a week before the ceremony makes it far easier to challenge later, and it is a hard way to start a marriage.

If the wedding is close and you have run out of time, you can sign a marriage contract after the wedding instead. In Canada, a marriage contract can be made before or during the marriage, and many US states also recognise agreements made after marriage, though some apply stricter rules to them.

The conversation itself

Many couples worry that raising a prenup signals distrust. The opposite framing is more accurate: a prenup signals financial maturity. You're acknowledging that you're two adults with financial histories, possibly with children or family obligations, who are choosing to be clear about what you each bring and what you each expect. That's the same conversation a good financial planner would have with you anyway. You're just having it in a form that has legal teeth.

A few things make the conversation easier: raise it early and privately, not in front of family; explain what you are worried about rather than presenting a finished document; and agree that each of you will have your own lawyer from the start.

What to do next

1. Start at least a few months before the wedding. Agree a date by which the agreement will be signed, well clear of the ceremony.
2. Each make a list of what you are bringing in. Assets, debts, income, business interests, expected inheritances and obligations to children from earlier relationships.
3. Exchange full financial disclosure. Statements, valuations and tax returns. Our financial disclosure checklist works for prenups as well as separations.
4. Talk about the principles before the clauses. What should stay separate, what should be shared, and what should happen to the home.
5. Each hire your own lawyer (or, in Quebec, involve a notary) to draft, review and finalise the agreement.

FairWell's prenup builder walks you through the key decisions before you meet with a lawyer, which can make the legal work more focused on what you both want. A lawyer then prepares the agreement, and each of you gets your own lawyer's advice.

Common questions

Is a prenup legally binding in Canada?

Yes, if it meets your province's requirements, such as being in writing, signed and witnessed in Ontario, or notarised in Quebec. A court can still set it aside for problems like hidden assets, pressure or unfairness, and it can never bind a court on child support or parenting.

Can we sign a prenup after we are married?

Yes. In Canada a marriage contract can be made before or during the marriage. Many US states also allow postnuptial agreements, though some apply stricter rules to them.

Do we each need our own lawyer?

It is strongly recommended everywhere and close to essential in practice. Separate advice is one of the main things courts look at when deciding whether to uphold an agreement, and in California a spousal support waiver is not enforceable without it.

Can a prenup decide custody or child support?

No. Courts decide parenting and child support based on the children's needs and best interests at the time of separation, whatever a prenup says.

How long before the wedding should we sign?

There is no single legal deadline in most places, but the earlier the better. Signing weeks or months ahead, after proper disclosure and advice, makes the agreement much harder to challenge.

This guide is legal information, not legal advice, and it is written for a general audience across Canada and the United States. Family law is provincial and state-based and changes over time. Before you rely on anything here for your own situation, confirm it with a qualified family lawyer in your province or state. FairWell can connect you with one through the professional directory.