How Long Do You Have to Live Together to Be Common-Law in Ontario?

Many couples ask whether there is a magic date after which they are legally treated like a married couple. The honest answer is that Ontario has no single clock. Different laws define an unmarried partner differently, and the length of time that matters depends on what you are trying to do.

This article walks through the main timelines, explains what counts as living together, and shows why one couple can be common-law for tax purposes but not for a support claim, or the other way around.

There is no one number for every purpose

Common-law is a label that different statutes apply when a couple meets the test in that statute. Because each law writes its own test, the number of months or years can change from one situation to the next.

The tests that most often matter are the Family Law Act for support, the Income Tax Act and CRA for taxes and benefits, and the Residential Tenancies Act for renting. The table below sets them side by side.

The main timelines side by side

Notice that a child can change the answer under several of these tests. A couple together for less than a year may still meet the tax or tenancy definition because they are parents of a child together.

The three-year rule and what counts as cohabiting

For support claims under section 29 of the Family Law Act, an unmarried person is a spouse if the couple cohabited continuously for a period of not less than three years. The Act says to cohabit means to live together in a conjugal relationship, whether within or outside marriage.

Both parts matter: the relationship must be conjugal, and you must be living together. The Court of Appeal for Ontario has upheld a finding that there needs to be some element of living together under the same roof, but that the lack of a shared residence is not determinative. The factors are considered together.

• Keeping separate addresses on paper does not decide the question if the couple in fact live together as a couple.
• The word continuous matters for the three-year rule, so gaps and breaks can raise questions that are worth discussing with a lawyer.

Time is not the only thing that matters

Even if you meet a common-law definition, that does not mean you get everything a married spouse would. A common-law partner may be entitled to spousal support, but support is not automatic. A claimant generally has to show a relationship responsibility that kept them from building their own career, a financial need after separation that the other spouse can meet, or a legal agreement providing for support.

Property works differently. Common law couples are not legally required to split property acquired while living together, and the equal-split rule for married spouses does not apply to them. A partner who contributed to property the other owns may still have a right to part of it, but may need to go to court to recover the contribution.

On death, a common law spouse does not inherit under Ontario's Succession Law Reform Act if the other partner dies without a will. A will is how most couples address this.

Short separations and tax rules

For taxes, once a couple cohabits in a conjugal relationship they are deemed to keep cohabiting unless they live separate and apart for at least 90 days because of a breakdown of the relationship. CRA also says a separation of less than 90 days caused by a breakdown does not interrupt the 12-month period.

That 90-day idea is a tax rule. Whether a break affects the three-year family law test depends on the facts, so it is worth getting advice if your relationship has had separations.

What to do next

• Write down when you started living together, any times you lived apart, and why.
• Identify which law matters to you: support, taxes, a lease, a pension or an estate.
• Gather proof of shared living, such as leases, mail, bills and joint accounts.
• Note whether you have a child together, since that can change the test.
• Consider a cohabitation agreement to set out property rights; it cannot decide parenting time or decision-making for children.
• If you sign or change such an agreement, put changes in writing and sign in front of a witness, and each partner should speak to a different lawyer.

If you are separating or disputing whether you were common-law, a family lawyer can apply the right test to your facts.

Frequently asked questions