In Ontario, married couples and common-law partners have very different legal rights upon separation. Married spouses who divorce are entitled to equal net family property division under the Family Law Act (FLA), equal possession of the matrimonial home, and Corollary Relief (child custody, support) under the federal Divorce Act. Common-law partners (who meet the FLA “spouse” definition – e.g. cohabited 3+ years or share a child) can obtain child support and spousal support under the FLA, but do not have automatic property division or equalization rights. Instead, a common-law spouse seeking a share of family assets must rely on equity remedies like unjust enrichment and constructive trust. This article explains these differences in depth – covering property division, spousal support, child support, cohabitation agreements, and practical steps to protect your rights (e.g. creating agreements, gathering evidence, understanding limitation periods). The discussion cites key statutes (Family Law Act, Divorce Act) and recent Ontario cases (ONSC and ONCA), to guide separated couples through their options.
Marriage vs Common-Law: Key Legal Differences
When an Ontario couple separates, legal rights depend on marital status. A married couple ends their marriage through divorce (governed by the federal Divorce Act) and settles family property under Ontario’s Family Law Act. A common-law couple (unmarried cohabitants) dissolves the relationship without divorce; only provincial family laws apply.
- Definitions: Under the FLA, a “spouse” for support purposes can include partners who are not married if they cohabited in a conjugal relationship for ≥3 years or have a child together. Anyone married, even civilly or voidably, is also a “spouse”.
- Property Equalization: Married spouses divide their net family property equally on divorce (each spouse’s assets minus debts from marriage and individual exclusions) under FLA ss.4–5. This equalization simply does not apply to common-law partners: as one Ontario family law guide notes, “the FLA property regime only applies to ‘spouses’ as defined in s.1 of the FLA. Therefore, only married spouses – and not cohabiting spouses – may benefit from an equalization of family property”. In other words, common-law partners have no automatic claim to divide assets.
- Matrimonial Home: There is special treatment for the family home. Regardless of title, both spouses have an equal right to possession of the matrimonial home. This protection is gender-neutral and applies to any person qualifying as “spouse” under the FLA (so it can include common-law once the 3‑year threshold is met). Even a marriage or cohabitation contract that attempts to cut off this right is void. However, note that property rights in the home differ: a married spouse is entitled to share of equity via equalization, whereas a common-law partner is not, unless a court orders a constructive trust due to contributions.
- Spousal Support: Married spouses can claim spousal support under the Divorce Act (Corollary Relief) or FLA; common-law “spouses” (3-year cohabitants or parent/child couples) may claim support under FLA Part III. Eligibility factors are similar (length of relationship, financial means, roles, etc.), but a family law article notes that courts apply FLA spousal-support rules to common-law couples.
- Child Support and Parenting: Child support follows the Federal Child Support Guidelines in either case. The guidelines mandate table-based support based on income, regardless of marriage. Parenting (custody/access) is now under the federal Divorce Act terminology (“parenting time”, “decision-making”), but applies to all parents (married or not). The FLA no longer has custody rules (replaced by federal law), except for children of unmarried parents in the former Children’s Law Reform Act.
Property Division: Equalization vs Unjust Enrichment
Equalization (married spouses): Upon divorce, each married spouse computes their net family property (total assets minus debts at valuation date, minus prescribed exclusions). The spouse with higher net wealth pays half the difference to the other. This “50/50” split is mandatory unless a valid marriage contract (prenup) or other exclusion applies. FLA s.5(1) sets out this formula. If a spouse’s NFP is negative, it’s set to zero in the calculation. Courts give the matrimonial home special treatment: its value enters into NFP (so a huge home benefit can trigger a big equalization payment).
No equalization for common-law: Cohabitants have no statutory net-family-property regime. Common-law partners who split cannot simply demand one-half of assets accumulated during cohabitation. As policy experts note, “family law requires no sharing between cohabitants on separation” in Ontario. Instead, an unmarried partner must bring a claim in equity: typically unjust enrichment or a constructive trust.
- Unjust Enrichment / Constructive Trust: The Supreme Court in Kerr v. Baranow (2011) reaffirmed that cohabiting partners who contribute to the other’s assets can claim restitution if three elements are met: (1) enrichment of one party, (2) corresponding deprivation of the other, and (3) no juristic reason (like a gift or contract) for it. If proven, a court may impose a constructive trust granting the claimant a share of specific property (often the family home) in proportion to contributions. The Kerr decision outlined four factors to examine whether their relationship was a “joint family venture” deserving a larger remedy: mutual effort, economic integration, actual intent of the parties, and priority of family over personal interests.For example, in Byrne v. Milner (2025), a 15-year common-law partner who renovated and managed the other’s house was found to have unjustly enriched the title-holder. The court granted the claimant an equitable interest: her contributions and labour improved the property, giving rise to a partial constructive trust. By contrast, if contributions are small or unrelated to asset value, courts may award only monetary compensation, not actual property.
- Judicial Precedent: Ontario courts have repeatedly noted the gap between marriage and cohabitation rights. One Ontario Court of Appeal blog notes that cohabiting spouses can only get compensation through unjust enrichment or cohabitation contract, not equalization. Another ONCA case reaffirmed that under FLA, the key test is a conjugal relationship per M. v. H. (1999) factors, and financial entanglement alone doesn’t automatically equalize assets.
Spousal Support: Married vs Common-Law
Married Spouses: On divorce, either party may apply for spousal support under the Divorce Act (s.15). Courts consider factors like length of marriage, roles during marriage, and needs (Divorce Act s.15.2, FLA s.33). Support can be lump-sum or periodic and is intended to address any economic hardship or disadvantage from the marriage or its breakdown. Spousal support orders can continue for decades or indefinitely, depending on age, health, and other factors (the “rule of 65” can apply).
Common-Law Partners: Unmarried cohabitants can seek spousal or partner support under the FLA Part III if they qualify as spouses (see definition above). The same general principles apply, but the length-of-relationship threshold remains important: under FLA, cohabitants must have lived together 3+ years (or one must have a child by the other) to claim support. Once that hurdle is met, support is possible. Murgia v. Murgia (ONSC 2019) and others have confirmed that former common-law spouses are entitled to claim support under FLA s.33, treating the 3-year rule as an eligibility test. If one partner had low income or was financially dependent (e.g. stayed home with children), courts may award spousal support to avoid unfair hardship.
Child Support: Both married and common-law parents are equally responsible for child support. The Federal Child Support Guidelines apply to all separated parents, married or not. The payor’s income and number of children determine a base table amount, with possible special or extraordinary expenses. Legal status does not affect the guideline calculation.
Parenting Time and Custody
Parenting arrangements (custody/access now called parenting time and decision-making) follow the best interests of the child standard, under either the Divorce Act or FLA/Children’s Law Reform Act if not married. In practice, Ontario courts apply the federal Divorce Act framework to all families. Separation agreements or court orders will set out parenting schedules. Both parents must contribute to child’s upbringing; if they separate, courts may award primary residence and support to one parent, and ordering parenting time for the other. The process is the same whether the parents were married or common-law.
Practical Guidance for Separation
1. Cohabitation or Separation Agreements: To protect rights, couples should consider a cohabitation agreement before or during their relationship. This legal contract (enforceable under FLA Part IV if signed properly) can clarify property division, support obligations, and maintain privacy. For example, a cohabitation agreement might waive an unjust enrichment claim or require full disclosure of assets – reducing litigation later. Similarly, married couples use marriage contracts (prenups) to override default equalization rules (FOCUS ON DISCLOSURE!). After separation, a detailed separation agreement can document terms (division of property, support amounts, parenting plan) which courts generally approve if fair and with legal advice.
2. Evidence and Documentation: Whether married or common-law, evidence is key. Common-law partners often need to prove their contributions or cohabitation length. Useful evidence includes joint leases/mortgages, photos, correspondence, shared financial accounts, wills naming each other, insurance or benefit designations, affidavits from witnesses, etc.
3. Timelines and Limitation Periods: In Ontario, claims for family property or support generally proceed in family court once a claim is issued (no fixed “deadline” in the FLA itself). However, any equity claim (unjust enrichment/ constructive trust) is subject to the Limitations Act, meaning it must be brought within 2 years of discovering the injustice (Ontario Limitations Act s.4). Thus, common-law partners should not delay too long after separation to pursue a claim.
4. Steps on Separation: Whether married or common-law, initial steps include: (a) Confirm status (were you married? did you meet the FLA 3-year or child criteria for “spouse”?). (b) Gather financial and legal documents (tax returns, title deeds, affidavits of support, etc.). (c) Consider negotiation or mediation before litigation: many issues can be settled by agreement. (d) If litigation is needed, consult a family lawyer promptly. The Ontario Rules of Civil Procedure (Family Law Rules) allow support, custody, and property claims to be made in an “application” proceeding.
5. Impact of New Laws: Ontario has recently reformed family law (2020 onwards), but these reforms mostly concern children. Currently, the FLA definition of spouse remains 3 years/child; no Ontario law yet mandates property sharing for common-law partners. (However, note that Saskatchewan, Manitoba, Québec now have laws or codes requiring equal division for unmarried couples. Ontario does not yet – it’s been called a “gap” in the law.)
In Summary
- Married Couples: Get equal property division (FLA), equal home rights, and can divorce under federal law. Spousal support follows Divorce Act or FLA rules; child support by guidelines.
- Common-Law Couples: Must prove spousal status (3+ years or child) to access any rights. They do not get automatic property division. To claim share of property, they need an unjust enrichment/constructive trust remedy (SCC Kerr v Baranow factors apply). They can claim spousal support (FLA s.33) and must pay child support just the same.
Couples separating should consult a lawyer to review statutes like FLA ss.19,29,33 and consider agreements. Resources such as the [Ontario Family Law Act] or [Canadian Divorce Act] can clarify rights, and reputable firms (e.g. via TCZ Law’s blogs) offer practical guides. Understanding these differences early – e.g. creating cohabitation agreements, fully disclosing finances, documenting contributions – is the best way to protect each person’s interests at the time of separation.