- Ontario has no single definition of common-law, and the test changes with the law you are asking about.
- For family law support, unmarried partners are spouses after cohabiting continuously for not less than three years, or sooner if they are parents in a relationship of some permanence.
- Living under one roof is not always enough, and for Ontario Works, sharing finances alone does not make co-residents spouses.
Many people ask whether they are legally common-law. Maybe you have a new partner who stays over most nights, or you are roommates who get along well, or you are a couple who keep separate homes. The honest answer is that it depends on which law is asking.
This article explains the main tests used in Ontario and federal law so you can see where you might fall. It is general information, not a conclusion about your own case.
There is no single common-law test
Under the Family Law Act, to cohabit means to live together in a conjugal relationship, whether or not the couple is married. The general definition of spouse in that Act covers married people, which governs property division and the matrimonial home, and it does not include unmarried partners.
Other laws then widen the idea for their own purposes. That is why you can be treated as a spouse for one purpose and not for another.
Support under the Family Law Act
For support only, the Family Law Act widens spouse to include two unmarried persons who have cohabited continuously for not less than three years. Unmarried partners are also spouses for support, however long they lived together, if they cohabited in a relationship of some permanence and are the parents of a child as set out in the Children's Law Reform Act.
Every spouse, including one of these common-law spouses, must support themselves and the other spouse according to need, to the extent they are able.
Tax, immigration and benefits compared
| Law or program | General test |
|---|---|
| Income Tax Act | Cohabiting in a conjugal relationship throughout the 12-month period ending at that time |
| Income Tax Act, with a shared child | A cohabiting conjugal partner who is a parent of the taxpayer's child counts even before 12 months |
| Immigration and Refugee Protection Regulations | Cohabiting in a conjugal relationship for at least one year |
| ODSP | Declaration, support obligation, or three months in the same dwelling with ties consistent with cohabitation |
| Ontario Works | Financial, social and familial interdependence must all be present |
For tax, once partners cohabit they are deemed to keep cohabiting unless they have lived separate and apart for at least 90 days because the relationship broke down.
Roommates, new couples and separate homes
- Roommates: sharing finances alone does not make co-residents spouses for Ontario Works. A conjugal relationship is part of the family law and tax tests.
- New couples: the time-based tests mean a short relationship may not meet them, although a child together can change the result for support and tax.
- Separate homes: the family law and tax tests both depend on cohabiting, meaning living together in a conjugal relationship. Spending nights together may not be enough, so the facts matter.
Not being spouses has real consequences. Ontario does not divide property between common-law couples when they separate, and each partner keeps the property they bought. A common-law spouse also does not inherit under the Succession Law Reform Act if there is no will.
What to do next
If you want certainty, you can set out your own terms. Two unmarried people who are cohabiting, or who intend to cohabit, may make a cohabitation agreement about their rights and obligations, including property and support. It is unenforceable unless it is in writing, signed by the parties and witnessed.
- Note which law or program you are asking about, since the test differs.
- Keep records of your shared address, bills and any shared lease or ownership.
- Check whether any CRA or benefit reporting is needed after a change.
- Consider a cohabitation agreement, with each partner speaking to a different lawyer.
- Get legal advice if a dispute or benefit decision turns on your status.
Frequently asked questions
How long do you have to live together to be common-law in Ontario?
It depends on the law. For family law support it is cohabiting continuously for not less than three years, or a relationship of some permanence with a child together. For tax it is 12 months, or sooner with a shared child.
Do common-law partners share property when they separate?
Ontario does not divide property between common-law couples when they separate, and each partner keeps what they bought. A partner who contributed to property the other owns may have a right to part of it, and may have to go to court if the owner does not agree to pay back the contribution.
Can I be a spouse for tax but not for family law?
Yes, because the tests differ. A person can meet the 12-month tax test before reaching the three-year support test, unless they have a child together.
Do I need a written agreement?
Not required, but a cohabitation agreement can set out property and support terms. It must be in writing, signed and witnessed to be enforceable.
Sources
- Family Law Act, R.S.O. 1990, c. F.3 (e-Laws) — Ontario e-Laws
- Ontario.ca – Dividing property when a marriage or common law relationship ends — ontario.ca
- Income Tax Act, s. 248(1) (Justice Laws) — Justice Laws (federal)
- CRA – Marital status — canada.ca
- Immigration and Refugee Protection Regulations, SOR/2002-227, s. 1 — Justice Laws (federal)
- Ontario.ca – Administering estates — ontario.ca
- ODSP Income Support Policy Directive 2.3 – Spouse — ontario.ca
- Ontario Works Policy Directive 3.3 – Co-residency — ontario.ca
Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.
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