When to Update a Domestic Contract After a Child or Provincial Move in Ontario

You signed a marriage contract before the wedding, or a cohabitation agreement when you moved in together. Life has since changed — maybe significantly. A child was born. One of you inherited a business. You moved from Alberta to Ontario. One spouse left the workforce. The financial picture that made your original agreement fair no longer exists.

Domestic contracts don't automatically update themselves. The provisions you signed years ago may no longer reflect your situation — and in some cases, the old agreement may actually be harder to enforce precisely because life has changed so dramatically. Knowing when to revisit an agreement (and how) is as important as getting the original right.

Why Life Changes Can Affect a Domestic Contract

A domestic contract is a snapshot of two people's financial situation, expectations, and intentions at a particular point in time. The Family Law Act allows courts to set aside agreements where enforcing them would cause unconscionable results — and while courts don't set aside agreements lightly, a clause that seemed reasonable when signed can look very different when circumstances have shifted.

Consider a few examples:

• Spousal support waiver signed before children: If the agreement was signed when both partners worked full-time and earned similar incomes, a blanket support waiver made sense then. If one partner later left the workforce for a decade to raise children — a predictable outcome neither party specifically addressed — enforcing that waiver may be much harder. Courts have indicated they will examine whether circumstances at the time of enforcement match the circumstances contemplated when the agreement was made.

• Property division tied to pre-existing assets: An agreement that identified which assets each party owned at signing doesn't automatically address assets acquired since then. If there is no clause addressing how future property is treated, you may be relying on the default Ontario rules — which may or may not match your intentions.

• Moving from another province: If you signed a domestic contract in British Columbia and then moved to Ontario, the contract may refer to B.C. legislation, use B.C. legal terminology, or address rights that don't exist the same way under Ontario's Family Law Act. Ontario courts will typically apply Ontario law once you're resident here — potentially producing outcomes the original contract didn't anticipate.

Key Life Events That Should Prompt a Review

1. The Birth or Adoption of a Child

Children change nearly every aspect of family law. They affect:

• Whether a spousal support waiver remains appropriate (one parent may significantly reduce work)
• Parenting and childcare expenses that weren't anticipated
• Life insurance and estate provisions in the agreement
• The practical meaning of clauses about the matrimonial home, since children's stability is a factor in any future court application

Note: Any clause in a domestic contract that purports to pre-determine child support or restrict the court's jurisdiction over children is not binding. But the surrounding financial provisions may need updating when children arrive.

2. Moving to Ontario from Another Province

Ontario has distinct rules on:

• Equalization of net family property (most provinces don't have this exact regime)
• The matrimonial home (extraordinary statutory protections exist in Ontario that don't exist in most other provinces)
• Support obligations for common-law partners

An agreement drafted under another province's law may not map cleanly onto Ontario law. You should have an Ontario family lawyer review any existing domestic contract within a reasonable time of establishing Ontario residency.

3. A Significant Wealth Change

If one partner has inherited substantially, sold a business, received a large windfall, or conversely taken on significant debt, the financial balance that underpinned the original agreement may no longer hold. An agreement that seemed balanced when both parties had roughly similar net worths can look very one-sided — and become more vulnerable to challenge — after a major financial shift.

4. A Career Change That Affects Income

If one party left a high-income career, experienced a significant salary increase, or became self-employed, the support provisions (or support waiver) in the original agreement may no longer be appropriate.

5. Long Passage of Time

A cohabitation agreement signed in the first few months of a relationship, or a marriage contract signed just before the wedding, was made with limited life experience together. After five or ten years — particularly if children are involved — it's worth asking whether the original terms still reflect what both parties would choose today.

How to Update a Domestic Contract in Ontario

An existing domestic contract is amended by a written amending agreement that:

• Identifies the original contract and the changes being made
• Is signed by both parties
• Is witnessed by at least one witness per signature
• Should be accompanied by updated financial disclosure if the amendment touches financial provisions
• Should be reviewed with independent legal advice for each party

There is no restriction on how many times a domestic contract can be amended. Each amendment is a separate document that modifies the original and the two are read together.

If the changes are extensive — essentially a new deal — the parties may prefer to terminate the original agreement entirely and enter a new one. A lawyer can advise on which approach is cleaner given the scope of changes.

What If We Can't Agree on Changes?

If circumstances have changed significantly but both parties can't agree on an amendment, the options are:

• Mediation: a neutral mediator helps negotiate revised terms
• Legal advice and negotiation: each party's lawyer negotiates on their behalf
• Court application: if an existing agreement is causing real hardship or contains a provision a court would not enforce, an application to set aside or vary the agreement is possible — though expensive and uncertain

Frequently asked questions