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Prenuptial Agreement Laws In Ontario

Need To Know

A prenuptial agreement, or prenup, is a legal contract signed before marriage in Ontario, governed by the Family Law Act. It allows couples to decide how property, debts, and spousal support will be handled during the marriage or in case of separation, divorce, or death. To be valid, the agreement must be in writing, signed voluntarily, include full financial disclosure, and be fair. Independent legal advice is strongly recommended. Prenups cannot address child support or custody arrangements. If contested, courts may invalidate agreements that are unfair, lack disclosure, or were signed under pressure.

What Are Prenuptial Agreements?

A prenuptial agreement, often called a prenup, is a legal contract signed by a couple before they get married. In Ontario, prenuptial agreements fall under the umbrella of marriage contracts and are governed by the Family Law Act. These agreements allow couples to proactively decide how their property, assets, debts, and spousal support will be handled during their relationship and in the event of separation, divorce, or death.

How Does a Prenup Work in Ontario?

In Ontario, a prenup works by clearly outlining each partner’s rights and obligations during and after the marriage. Once signed, it becomes a binding legal agreement – as long as it meets the legal requirements. These contracts can help avoid lengthy and expensive legal disputes if the relationship ends in divorce.


What Are Prenuptial Agreement Laws In Ontario?

Prenuptial agreements in Ontario are governed by the Ontario Family Law Act, which permits spouses and soon-to-be-spouses to create domestic contracts, including marriage contracts. These laws recognize the importance of allowing couples to privately organize their financial affairs.

However, for the contract to be enforceable, certain requirements must be met. For example, both parties must enter into the agreement voluntarily and with full understanding of its implications. Courts will uphold a prenuptial agreement unless there are legal deficiencies or it is deemed “unconscionable.”  We’ll go through a few things that you need to know to make a valid prenup below.


Key Legal Requirements for a Valid Prenuptial Agreement in Ontario

To be a valid prenuptial agreement under Ontario law, your agreement must meet the following criteria:

  • Written agreement: A verbal agreement is not enforceable – because it’s hard to prove who said what in the future if there was nothing written down.
  • Voluntarily signed by both parties: Each party must sign the agreement voluntarily – if someone is pressured or manipulated to sign, it’s unlikely that your agreement will be enforced later.
  • Full financial disclosure: Both parties should provide an honest and complete picture of their financial situation.  If either of you leaves something out, it is unlikely that the agreement will be seen as fair.
  • Reasonable and fair: While it’s not necessary for everything to be exactly equal for an agreement to be fair, a court is unlikely to uphold an agreement that puts one person at a significant disadvantage if the relationship ends.
  • Independent legal advice: While not strictly required, it is helpful for each person to get independent legal advice from a lawyer to ensure they understand and agree to the terms. We include an independent legal advice certificate with each Jointly agreement. 


What Can Be Included In A Prenup In Ontario?

Prenuptial agreements can cover a wide range of issues, including:

  • Division of property upon separation or divorce
  • Ownership of the matrimonial home (though special rules apply)
  • Management of family debts
  • Spousal support entitlements or waivers
  • Business ownership and asset protection
  • Financial responsibilities during the marriage
  • Inheritance rights and estate planning

What Can Not Be Included In A Prenup In Ontario?

Certain matters cannot legally be included in a prenup, such as:

  • Child support: This cannot be negotiated or waived. Courts decide this issue based on the best interests of the child at the time of separation. 
  • Custody and access arrangements: These are not binding in a prenup for the same reason.
  • Unfair or unconscionable terms: If a provision is extremely one-sided or unjust, it may be struck down.


How To Get A Prenup Agreement In Ontario

If you’re wondering how to get a prenup agreement in Ontario, here are the steps:

  1. Discuss your goals with your partner starting at least a few months before the wedding.
  2. Exchange full financial disclosure documents. You can get started on this for free with our property disclosure worksheet.
  3. Get Jointly. Our course and agreement builder will take you through what you need to know and empower you to build an agreement that fits your family. 
  4. Sign your agreement.
  5. Store copies safely and refer back to them as needed.

Prenups should not be rushed. Get started as early as possible to make sure you have time to have the discussions you need to have to make an agreement that feels right for both of you.


Can A Prenup Be Contested In Ontario?

Yes, a prenup can be contested in Ontario. If one person believes the agreement is invalid, they can ask the court to overturn it. Common grounds for contesting a prenup include:

  • One person failed to disclose significant assets or debts
  • One person did not understand the agreement
  • Coercion or pressure to sign
  • Unconscionable or unfair terms

What Can Make A Prenup Invalid In Ontario?

A court may declare a prenup invalid if:

  • It was signed under duress or without proper mental capacity
  • It fails to meet the legal requirements set out above
  • There was a material financial misrepresentation or nondisclosure
  • It is grossly unfair or contrary to public policy


FAQS

How much does a prenup cost in Ontario?

The cost of a prenup in Ontario varies. On average, couples can expect to pay between $2,000 and $5,000 to have a lawyer draft their prenup, depending on complexity and legal fees. More complex agreements or high-net-worth cases may cost more. 

With Jointly, your prenup costs $379.

How long does a prenup last in Ontario?

A prenuptial agreement lasts indefinitely unless it includes an expiry date or is formally revoked or replaced by another agreement. Changes in circumstance don’t automatically void it, but may affect its enforceability. It’s a good idea to review your agreement regularly, and update it when your life changes. 

Can you sign a prenup after marriage?

You can’t make a prenup after marriage, but you can enter into a postnuptial agreement, also known as a postnup, after the wedding. Postnups include the same subject matter and have the same requirements for validity as prenups. 

Can I write my own prenuptial agreement in Ontario?

Technically, you can write your own prenup. However, to create a valid prenuptial agreement that will hold up in court, it is crucial to follow Ontario’s legal requirements and provide full financial disclosure. DIY prenups often fail under scrutiny, so using Jointly or working with a lawyer in your area is strongly recommended.


Understanding prenuptial agreement laws in Ontario empowers you to protect your future and build your relationship on a foundation of clarity and trust. Jointly makes it easier to navigate the legal process and create agreements that reflect your shared goals—without unnecessary stress or expense.

Click Sign Up at the top of the page to get started today.

Amanda Baron

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