In Canada, a common-law relationship is defined as living in a conjugal relationship with a person whom you are not married to, if at least one of the following applies:  Common law is considered a de facto relationship, meaning that it must be established on a case-by-case basis according to the facts (though there are nuances, particularly with regard to the “12 continuous months” part). This contrasts to marriage, which is de jure, i.e. established by law.  However, that’s just the federal definition. The legal definitions of common law do vary provincially.   For example, in British Columbia, the Family Law Act considers common-law partners as spouses only after two years of cohabitation.   In Ontario, that stretches to three years, although it does go back down to one year if the couple has a child together, by birth or adoption.   Related: Six financial signs your relationship is headed to the next level