Can We Change or Cancel Our Marriage Agreement After Signing in British Columbia?

This answer covers the law of British Columbia.

Yes, you can usually change a marriage agreement together, but one spouse cannot simply cancel it alone. Spouses may make agreements about dividing property and debt, and the Family Law Act does not limit when they are made, so spouses who are already married can make a property agreement during the marriage. The Act's set-aside rules apply to a written agreement with each spouse's signature witnessed by at least one other person.

The same person may witness both signatures, and the Act does not require notarization, a commissioner or a lawyer's signature. If only one of you wants out, the Supreme Court may set aside or replace all or part of a witnessed agreement only if a listed circumstance existed when it was made, such as non-disclosure, taking advantage of vulnerability, or not understanding the agreement. Even then, the court may decline to act if it would not make a substantially different order.

Changed circumstances alone are not a listed ground for property agreements, although the court may act if an agreement is significantly unfair, weighing the time passed, the wish for certainty and how much you relied on it. Spousal support and parenting terms follow different rules, so a lawyer can confirm where you stand.