What Happens to a Prenuptial Agreement if You Move Out of Ontario?

The Portability of Prenuptial Agreements within Canada

Family Law is Provincial

In Canada, family law is not handled at the federal level but is instead governed by each province and territory. This means that the Ontario Family Law Act regulates marriage contracts within Ontario, while other provinces, such as British Columbia or Alberta, rely on their own statutes. Although the overall principles are similar—such as ensuring fairness, full financial disclosure, and independent legal advice—the exact rules can vary. Moving to another province may expose your contract to slightly different standards of review.

Recognition of Ontario Marriage Contracts

Generally, Canadian provinces respect and uphold valid Ontario prenuptial agreements. Courts in other jurisdictions are reluctant to disregard a properly executed contract, particularly if it was made voluntarily, with full disclosure, and each spouse received independent legal advice (ILA). For example, an Ontario marriage contract that sets out property division or spousal support obligations will typically remain enforceable in another province.

Possible Adjustments

While your Ontario prenuptial agreement will often be recognized, certain provisions may need review or adjustment to reflect local laws:

• Property Division: Ontario applies an equalization of net family property system, while provinces like British Columbia use a family property division If your contract excludes or alters how property is divided, the way another province interprets it may differ.
• Spousal Support: Support guidelines, including duration and amount, are influenced by each province’s interpretation of fairness. A clause that seems enforceable in Ontario could be challenged in another jurisdiction if it’s found to be unfair.
• Formalities and Updates: Some provinces impose specific procedural requirements. For example, British Columbia’s Family Law Act places greater emphasis on unconscionability and fairness at the time of enforcement. If you relocate, you may need to update your contract to ensure compliance with your new province’s laws.

Moving Outside of Canada – International Considerations

Jurisdictional Differences

When you leave Ontario and move abroad, the recognition of your prenuptial agreement becomes more complex. Each country has its own marital property regime, and not all follow the common law framework used in Ontario. For instance, many European and Latin American countries apply a community property system, where assets acquired during the marriage are automatically considered jointly owned. Civil law jurisdictions may also impose stricter limits on a couple’s ability to contract out of statutory rights. This means that even if your Ontario prenup is valid at home, a foreign court might not enforce it in the same way.

Choice of Law Clauses

To strengthen your agreement’s portability, many Ontario family lawyers recommend including a choice of law clause. While this doesn’t guarantee international enforceability, it provides a clear expression of the parties’ intentions and may persuade a foreign court to give weight to the contract. Without such a clause, courts outside Canada may default to applying their own local rules.

Enforceability Challenges

International enforcement is never straightforward. A foreign court may refuse to uphold an Ontario prenuptial agreement if it:

• Conflicts with local public policy (e.g., mandatory property rights or minimum spousal support protections).
• Was not executed with formalities required in that jurisdiction (e.g., notarisation in civil law countries).
• Is considered unfair or unconscionable at the time of separation.

Key Factors Courts Consider When Enforcing an Agreement

Voluntary Execution

One of the first questions a court will ask is whether both spouses signed the prenuptial agreement freely and voluntarily. If one party was pressured, misled, or did not have the opportunity to fully understand the terms, the contract may be set aside. Ontario courts in particular look closely at whether there was independent legal advice, which helps demonstrate that both spouses understood their rights and obligations at the time of signing.

Full Financial Disclosure

A prenuptial agreement is built on trust and transparency. If one spouse failed to disclose significant assets, debts, or income, the agreement could be challenged later. Ontario judges often stress that complete and honest financial disclosure is essential for validity. Without it, a court may rule that the agreement was unfairly obtained and refuse to enforce it.

Fairness at Time of Enforcement

Even if a prenup was validly executed years ago, courts retain the discretion to review it for fairness at the time of enforcement. Circumstances can change dramatically — one spouse may become ill, give up a career to raise children, or face financial hardship. If the agreement produces results that are grossly unfair or unconscionable, a court may set it aside or modify certain terms. In Ontario, the Family Law Act gives judges the power to intervene when enforcing the contract would lead to an inequitable outcome.

Best Practices When Relocating

Legal Review before Moving

Before relocating outside Ontario, it’s wise to arrange a legal review of your prenuptial agreement. Consulting a lawyer in the new jurisdiction can help you understand how your Ontario contract will be interpreted under local family law. This is particularly important if you’re moving to a province with different property division rules or to a country with a civil law or community property regime.

Amending or Reaffirming the Agreement

In many cases, couples may choose to amend or reaffirm their agreement once they move. This ensures the contract reflects both the original Ontario terms and the requirements of the new jurisdiction. For international relocations, lawyers often recommend creating a mirror agreement—a parallel contract drafted under local law that mirrors the Ontario agreement’s intent.

Language and Witness Requirements

Formalities matter. Some jurisdictions require prenuptial agreements to be drafted in the local language, notarized, or signed before specific witnesses to be legally binding. For example, in many civil law countries, a contract that is not notarized may be unenforceable. By adapting your agreement to meet these local procedural requirements, you reduce the risk of a future dispute about its validity. Ensuring the document complies with both Ontario and the new jurisdiction’s standards is the safest way to protect your intentions.

Common Mistakes Couples Make

Assuming Global Validity

A frequent misconception is that once a prenuptial agreement is signed in Ontario, it will automatically be enforceable anywhere in the world. In reality, every province and country applies its own family law framework, and courts may impose different requirements. Assuming global validity can leave couples vulnerable, especially when moving to jurisdictions with community property or civil law systems.

Failing to Update After Major Life Events

Prenuptial agreements should not be treated as “set it and forget it” documents. Major life changes — such as marriage, having children, or acquiring significant property in a new jurisdiction — can impact the fairness and enforceability of the contract. Ontario courts, like those in other provinces, may set aside an agreement if it no longer reflects the couple’s circumstances.

Not Seeking Legal Advice Abroad

Another common mistake is neglecting to seek local legal advice when relocating outside Ontario. Foreign jurisdictions may impose unique requirements regarding language, notarisation, or mandatory rights that differ from Canadian standards. By consulting a lawyer abroad, couples can adapt their Ontario prenup or create a mirror agreement, increasing the likelihood of recognition.

When to Consider Drafting a New Agreement

Significant Relocation

A move from Ontario to another province — or especially to another country — may create a legal environment very different from the one in which your original prenuptial agreement was drafted. For example, provinces such as British Columbia or Quebec apply family property division differently than Ontario. Internationally, many countries operate under community property or civil law systems. If your relocation involves such significant changes, it may be best to draft a new agreement that clearly reflects the laws of your new jurisdiction while preserving your original intentions.

Changes in Financial Circumstances

Life rarely stands still. If you acquire new assets, inherit property, assume substantial debt, or establish a business after relocating, your Ontario prenuptial agreement may no longer capture your financial reality. Courts give considerable weight to fairness at the time of enforcement, and agreements that fail to address current financial circumstances risk being challenged. Drafting a new agreement can ensure your contract remains up to date and enforceable.

Mutual Agreement

Sometimes both spouses agree that revisiting the original prenup makes sense. This may be because the agreement no longer reflects their mutual intentions or because they want to reduce uncertainty by aligning with local legal requirements. Creating a new agreement — whether in Ontario before a move, or in the new jurisdiction after relocation — can strengthen clarity, reduce potential disputes, and give both parties renewed peace of mind.