LIMITED TIME: Get 10% off with the code GETJOINTLY

Share this article:

Challenging a Marriage Contract

Can My Prenup Be Challenged In Court?

Need To Know

Prenups are legally binding in Canada—but only if done right. They must be fair, transparent, and follow legal formalities to hold up in court. This guide breaks down when and how a prenup can be challenged or overturned, the red flags that make them vulnerable, and how to protect yours from being invalidated. Whether you’re contesting a prenup or creating one, understanding what courts look for is essential.

Prenuptial agreements, or prenups, are a popular legal tool used by couples to clarify how property, assets, and debts will be managed during their relationship and in the event of separation, divorce, or death. But while they can provide peace of mind, they aren’t immune from legal scrutiny. Many people ask, can you challenge a prenup? or can a prenup be overturned in court? The short answer is yes – but only under certain conditions.

This guide explores everything you need to know about challenging a prenuptial agreement in Canada, including what makes a prenup invalid and what courts look for to assess whether a prenup is enforceable.


Are Prenups Legally Binding?

One of the most common questions that we get at Jointly is: are prenups legally binding in Canada? The answer is generally yes – if they meet certain legal requirements.

In Canada, prenuptial agreements are governed by provincial and territorial family laws. Although each jurisdiction has its own legislation, prenups are generally legally binding across the country, provided they are:

  • Made in writing
  • Signed voluntarily by both parties
  • Signed with full financial disclosure
  • Witnessed

However, just because prenups are legally recognized does not mean they are automatically enforceable. Courts can and do strike them down under certain conditions.


Can a Prenup Be Challenged in Court?

Yes. Challenging a prenuptial agreement is possible in Canada, and courts will carefully review the facts to determine whether to uphold or invalidate the agreement.

Common prenup scenarios that lead to legal challenges are:

  • One person feels pressured into signing
  • One or both people hid or misrepresented financial assets
  • The terms of the agreement seem unfair or one-sided
  • Only one party had legal advice

If you’re considering contesting a prenuptial agreement, keep reading to determine what you’ll need to prove in order for your challenge to succeed.


Reasons Why A Prenup Might Be Challenged

When contesting a prenuptial agreement, certain red flags are more likely to lead a court to declare a prenup invalid. These include:

  1. Lack of Independent Legal Advice If one party didn’t have their own lawyer, the court might consider whether they fully understood the implications of the agreement.
  2. Coercion or Duress If someone was pressured to sign the prenup under threat or emotional manipulation, the court may rule that the prenup wasn’t entered into voluntarily.
  3. Inadequate Financial Disclosure One of the most common reasons for challenging a prenuptial agreement is if one person didn’t disclose all their assets or debts.
  4. Unconscionable Terms Agreements that are so one-sided that they shock the conscience of the court are vulnerable to being struck down.
  5. Procedural Irregularities If the prenup wasn’t signed, dated, or witnessed properly, that can be enough to call its validity into question.


What Makes A Prenup Invalid in Court?

So, what makes a prenup invalid in the eyes of the court? Let’s break it down.

1. Failure to Follow Legal Formalities

The agreement must be in writing and signed by both parties. Failing to meet these requirements could render the prenup unenforceable.

2. Lack of Full Disclosure

If either party fails to disclose significant assets, liabilities, or income sources, the agreement can be set aside.

3. Unfair or Oppressive Provisions

Courts will not enforce agreements that are grossly unfair, such as denying a spouse any support regardless of the marriage’s duration or sacrifices made (like one person giving up their career to care for children).

4. Absence of Legal Representation

While not legally required, having a lawyer or using a lawyer-developed platform like Jointly greatly reduces the risk of a prenup being challenged. Contract drafting is technical. If you wrote your own prenup and didn’t adhere to family legislation or legal standards of contract drafting, your prenup could be found to be invalid.

5. Last-Minute Signing

If the agreement is signed too close to the wedding date, courts may infer duress or lack of time for proper review.


How Do Courts Decide Whether a Prenup Is Enforceable?

When reviewing whether a prenup can be enforced, courts look at both the form (how it’s written) and the substance (what it says) of the agreement. The judge will consider:

  • Whether the agreement was entered into freely
  • If both parties understood the terms
  • Whether the agreement is fair
  • The context and circumstances at the time of signing

What Happens if the Court Finds the Agreement Unenforceable?

If the court finds the prenup invalid or unenforceable, it will not be used to decide property division or spousal support. Instead, the court will apply provincial family law, which often involves equal division of assets and determination of support based on need and contribution. Provincial legislation is intended to provide an outcome that is reasonably fair – but it may not align with what you and your partner would have decided for yourselves in a prenup.


How to Void a Prenup (or Try)

Trying to overturn a prenup is an uphill battle, but here are the steps typically involved:

  1. Hire an experienced family lawyer who understands both contract and family law.
  2. Gather evidence of duress, coercion, or misrepresentation.
  3. Review the agreement for procedural flaws.
  4. File a legal application in the appropriate court.

Courts will require compelling evidence to set aside an agreement. Remember, the burden is on the person contesting the prenuptial agreement to prove its invalidity. That means that you need to gather everything you can to show the court that what you’re saying is true. If you know your partner hid assets from you, can you prove it? If you were pressured into signing the agreement on the day of your wedding, do you have text messages or emails backing that up? The rules of evidence in court are complicated. If you have the means to hire a family lawyer in your area to assist you with challenging your prenup, you should do so.


How to Protect a Prenup From Being Challenged

If you want your prenup to hold up in court, follow these best practices:

  • Make Full Financial Disclosure: List all assets, debts, and income. Be fully transparent. If you hide anything, your prenup is at risk of being overturned.
  • Avoid Last-Minute Agreements: Give each party enough time to review and reflect. The best practice is to start the conversation several months before the wedding at the latest.
  • Ensure Fairness: Avoid one-sided terms. A prenup doesn’t have to be exactly equal to be fair, but it does need to recognize and assign value to each partner’s contributions to the relationship.
  • Follow Formal Requirements: Use a platform like Jointly to make your prenup to ensure that your agreement is drafted in clear language and aligns with provincial legal requirements. Sign, date, and witness the agreement properly. 
  • Get Independent Legal Advice: While not required for enforceability in most provinces, it can be helpful for each person to review their Jointly agreement with their own lawyer and get what’s called a certificate of independent legal advice. This extra step is valuable, if you can afford it.

When done correctly, a prenup can be a powerful and enforceable document that protects both partners.


Final Thoughts

While prenups are legally binding in Canada, they aren’t immune from challenge. Whether you’re asking, can you challenge a prenup, can a prenup be overturned, or what makes a prenup invalid, the key takeaway is this: prenups must be created with care, fairness, and transparency.

If you’re concerned about the validity of your existing prenup or want to draft a new one that will hold up in court, get started with Jointly. Our platform is accessible, affordable, and provides legally-informed guidance to help you create strong, clear agreements from the start.

Amanda Baron

Get your prenup or cohabitation agreement

Is Jointly right for you?

Find out in one minute by taking our quiz ↴

Screening form

Jointly is only suitable where both partners are adults. Send us a note if you have any questions!

If one or both of you are not completely honest about your assets or debts, a judge could later decide that the agreement was unfair and decide not to enforce it if the relationship ends. Jointly is not a good fit for you unless you're prepared to share details about your assets and debts with your partner.  Send us a note if you have any questions!

Jointly is not able to handle the separation of a jointly operated business. Send us a note if you have questions!

Jointly does not support planning for property on reserves. Send us a note to let us know what you'd like to see incorporated into our future plans!

At present, Jointly is not able to support committed polyamorous relationships. Send us a note to let us know what you'd like to see incorporated into our future plans!

Relationship agreements which include parenting arrangements are not enforceable unless you are already separated or thinking about separating. Because of this, Jointly does not have the option to include parenting arrangements that would apply if your relationship ends . Send us a note if you have any questions!

You should not sign a relationship agreement if someone is forcing you to do so or if there is abuse in your relationship. Please talk to a lawyer, who can help you navigate this situation.

Jointly may be a good fit for your relationship!

Learn More

Cohabitation Agreement vs Prenup

How Does A Prenuptial Agreement Work?

Pros and Cons of Prenuptial Agreements

When Do You Become Common Law?

The best time to make a relationship agreement is when you move in together.

The next best time is now.

Learn

FREE

Build

$379

Learn

FREE

Build

$379