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№ 77 Family Law

Can a Court Set Aside a Marriage Agreement in BC?

If you regret signing a marriage agreement, learn the grounds a British Columbia court uses to set it aside, and what makes that hard or easier.

Family Law5 min readTSLBy the Treadstone Law Team · British ColumbiaUpdated November 6, 2026
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Key takeaways
  • The Supreme Court can set aside a witnessed property agreement only on listed grounds that existed when it was signed, or if it is significantly unfair.
  • Even when a ground is proven, the court may decline to act if its order would not be substantially different from the agreement.
  • Regret alone is not a listed ground, so the facts around how and why you signed matter most.

You signed a marriage agreement, and now you wish you had not. Maybe you did not understand it, maybe you were not shown everything your spouse owned, or maybe life has simply changed. You want to know whether a British Columbia court will undo it.

The Family Law Act gives the Supreme Court a power to set aside or replace all or part of these agreements, but it is deliberately limited. Understanding the grounds helps you judge whether your situation is likely to fit.

This article covers the law of British Columbia.

Which agreements the court can review

The Act's set-aside regime for property agreements applies to a written agreement about dividing property and debt with the signature of each spouse witnessed by at least one other person. The same person may witness both signatures.

If your agreement was signed but not witnessed, it is not automatically void. The court may apply the set-aside rules to an unwitnessed written agreement if it is satisfied that doing so is appropriate in all the circumstances, but such an agreement is not clearly within the protected regime.

The grounds for a property agreement

The court may set aside or replace all or part of a witnessed property agreement only if one of the following existed when the agreement was made:

GroundIn plain words
Failure to discloseA spouse did not disclose significant property or debts, or other information relevant to negotiating the agreement
Improper advantageA spouse took improper advantage of the other's vulnerability, including ignorance, need or distress
Lack of understandingA spouse did not understand the nature or consequences of the agreement
Common law groundsOther circumstances that would make a contract voidable under the common law

The focus is on what was true at signing. A change in your feelings afterward does not by itself fit any of these grounds.

The "significantly unfair" route and the court's discretion

Even where none of those circumstances existed, the court may set aside or replace all or part of a property agreement if it is significantly unfair. For property agreements, the court considers the length of time since the agreement was made, the spouses' intention to achieve certainty, and how far they relied on its terms.

There is also a safeguard against pointless orders. Where a ground is proven, the court can still decline to act if, on all the evidence, it would not replace the agreement with an order substantially different from the agreement's terms.

Spousal support, children and different rules

Spousal support agreements have their own regime. Where spouses have a written, witnessed support agreement, the court may not make a spousal support order unless all or part of the agreement is set aside. The grounds are similar, but they refer to failure to disclose income as well as significant property or debts.

A spousal support agreement, including a waiver, can also be set aside if it is significantly unfair. There the court considers the time passed, changes since the agreement in a spouse's condition, means, needs or other circumstances, the intention to achieve certainty, reliance on its terms, and how far it meets the objectives of spousal support. Those objectives include recognizing economic advantages or disadvantages, apportioning the financial consequences of child care, relieving economic hardship, and promoting economic self-sufficiency within a reasonable period. The court may also decline to act if its order would not be substantially different, and may apply the rules to an unwitnessed agreement if appropriate.

Child-related terms work differently. An agreement respecting child support is binding only if it was made after separation, or when the parties were about to separate and meant it to take effect on separation, so child support terms in a marriage agreement signed earlier are not binding as such. Where a child support agreement is binding, the court may set aside or replace all or part of it if it would make a different order after considering the matters in the Act. Parenting arrangements follow a similar timing rule: an agreement is binding only if made after separation, or when the parties are about to separate and it is meant to take effect on separation, so parenting terms in a marriage agreement are not binding. Where a parenting-arrangements agreement is binding, the court must, on a party's application, set aside or replace all or part of it if it is not in the child's best interests.

What to do if you want to challenge an agreement

The Province notes that, for property orders, the time limit for unmarried couples runs from the date of separation and for married couples from the divorce order, each being two years. Whether and how that applies to an application to set aside an agreement depends on your circumstances, so confirm it with a lawyer.

Frequently asked questions

Can I set aside an agreement just because I regret it?

No. The court can set aside a witnessed property agreement only if a listed circumstance existed when it was made, or if it is significantly unfair. Regret on its own is not a listed ground.

Is an unwitnessed agreement automatically invalid?

No. The court may apply the set-aside rules to an unwitnessed written agreement if it is satisfied that is appropriate in all the circumstances. It is still not clearly within the protected regime.

What if I did not know about my spouse's assets?

A spouse's failure to disclose significant property or debts, or other relevant information, is a listed ground when it existed at signing. Whether it succeeds depends on the facts, and the court may still decline to act if its order would not be substantially different.

Can a spousal support waiver be undone?

Possibly. A waiver is allowed, but the court may set aside or replace a spousal support agreement, including a waiver, on the listed grounds or if it is significantly unfair.

Sources

Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. British Columbia laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a lawyer who practises in British Columbia. Reach us at 1-844-900-1070 or send our Team a message.

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