Can we change or cancel our cohabitation agreement later in Ontario?

Yes. A cohabitation agreement, like any domestic contract under Ontario's Family Law Act, can be amended or revoked at any time by mutual agreement of both parties. To change the agreement, both parties sign a written amendment that identifies the clauses being altered and sets out the new terms. To cancel the agreement entirely, both parties sign a written revocation.

In both cases, the same safeguards that apply to the original agreement are good practice for the amendment: written form, signatures, witnesses, financial disclosure if relevant, and independent legal advice. An informal verbal agreement to change a domestic contract is not reliable in Ontario — changes should always be in writing.

Life events that commonly trigger a review of a cohabitation agreement include: purchasing or selling property together, one partner becoming self-employed or taking a career break, having a child, receiving a significant inheritance, or a major shift in the financial balance between partners. Some agreements include a built-in review clause (for example, a review every five years) to prompt the conversation. If the couple marries, the cohabitation agreement converts to a marriage contract automatically, which is itself a reason to review its terms and ensure they still reflect what the couple intends.