Cohabitation Agreements and Marriage Contracts in Ontario
Cohabitation agreements are entered into by couples who are living together or are about to start living together. Marriage contracts are entered into by couples who are about to get married or are already married. Under Ontario law, they are both types of “domestic contracts” and, when properly done, are enforceable in our courts. For couples that are coming into a relationship with property, entitlements, obligations and/or children from a previous relationship, they are a “must do”.
Both agreements can address:

When Are These Agreements Appropriate (and When Are They Not)?
Cohabitation agreements and marriage contracts are appropriate in many situations, including:
Blended families: When one or both partners have children from previous relationships and want to protect inheritances or property.
These agreements are also useful for couples who simply want clarity and peace of mind about their financial future. Ironically, it is usually easier for a couple to agree on how they will separate when they are fresh into their relationship and getting along, than when their relationship is over and their communications have soured.
However, cohabitation agreements and marriage contracts may not be appropriate when:
In such cases, the agreement may be challenged and even set aside by the court. It is therefore essential that both parties understand the terms and enter into the agreement voluntarily.
When considering such an agreement, it is also important to think about how the parties’ lives may change in the future. For example: could their careers and earning potential be affected by starting a family? What if health issues arise? Thinking ahead and planning for such circumstances can create more flexible and durable agreements that provide for such change and are more likely to stand the test of time.
What Professionals Are Involved?
Creating a valid and enforceable cohabitation agreement or marriage contract typically involves:
Family Lawyers
Each party should retain their own lawyer to:
This ensures that the agreement is fair, informed, and less likely to be challenged later.
Financial Advisors or Accountants
In more complex cases, financial professionals may help:
This is especially important when the agreement involves business interests, trusts, or significant investments.
Estate Planning Professionals
Marriage contracts often intersect with wills and estate plans. Lawyers or advisors may coordinate the agreement with:
This ensures that the agreement aligns with the couple’s long-term goals and avoids conflicts between family law and estate law.

How It Works
The process of creating a cohabitation agreement or marriage contract typically follows these steps:

Initial Consultation
The parties exchange full and honest disclosure of their financial situation, including:

Financial Disclosure
The parties exchange full and honest disclosure of their financial situation, including:
This disclosure is critical. To make agreements about finances and property, both parties must understand each other’s holdings, income and debt. Without such disclosure, the agreement may be vulnerable to challenge.

Drafting the Agreement
The lawyers draft the agreement based on the parties’ instructions. Common clauses include:
The agreement may also include review clauses, dispute resolution mechanisms, and provisions for future changes.

Independent Legal Advice
Each party reviews the draft with their own lawyer. The lawyer explains the terms, confirms understanding, and signs a Certificate of Independent Legal Advice.
This step is important to enforceability. Courts are more likely to uphold agreements when both parties had legal advice.

Signing and Storage
The agreement is signed and witnessed. Each party keeps a copy, and the lawyers may retain originals or a scanned copy of an original. The agreement can be referenced or filed with the court if needed in the future.
What Happens If We Separate Without an Agreement?
Without a cohabitation agreement or marriage contract, Ontario’s default family law rules apply:
An agreement allows couples to modify, or in some cases opt out of, these default rules and create their own framework.


Can These Agreements Be Changed or Cancelled?
Yes. Cohabitation agreements and marriage contracts can be:
When a change is made to a marriage contract or cohabitation agreement, the change must be made in writing and signed with the same formalities as the original agreement. It’s wise to seek legal advice before making changes.
Common Questions About Cohabitation Agreements and Marriage Contracts
Yes, if properly drafted, signed, and supported by financial disclosure and independent legal advice.
Yes. Marriage contracts can be signed before or after marriage. Cohabitation agreements can be signed at any time during the relationship.
To a very limited extent, you can address the right to direct a child’s education and moral training. But such agreements are not binding on the court in the event of a future dispute and in such cases are determined based on the child’s best interests at the time of separation.
Yes, but the waiver must be fair and informed. Courts may override waivers in cases of hardship or unfairness.
While not strictly required, independent legal advice is important and increases the chances that the agreement will be found fair and enforceable if challenged later.
Yes, but only in limited circumstances—such as lack of disclosure, duress, or unconscionability. The more work that goes into financial disclosure and fair negotiation of an agreement when it is created, the better the chance that it will be upheld in the event of a court challenge.
Yes. Agreements can be amended or replaced by mutual consent.

