What is a marriage contract in Ontario and is it the same as a prenup?

A marriage contract in Ontario is a domestic contract made under the Family Law Act by two people who are married or who intend to marry. It covers property rights, spousal support, and financial arrangements between the spouses, either before or during the marriage. What is commonly called a "prenuptial agreement" or "prenup" in everyday language is simply a marriage contract signed before the wedding ceremony.

If signed after marriage, the same agreement is sometimes called a postnuptial agreement, but Ontario law simply calls all of these "marriage contracts." There is no legal distinction between a prenup signed the week before the wedding and one signed years into the marriage — both are domestic contracts subject to the same rules.

Marriage contracts can address what happens to property if the marriage breaks down or on death, whether spousal support will be available, and how specific assets (a family business, inherited property, or real estate) will be treated. There are limits: a marriage contract cannot restrict the other spouse's right to possession of the matrimonial home during the marriage, and it cannot deal with custody or access to future children.