同居/普通法伴侣 Common-Law Partner
Under current Canadian law, couples of the same or opposite sex who have lived together in a conjugal relationship for more than one year is considered equal to being married. This relationship is called a common-law. Similar to a legally married couple, both individuals bear obligations and responsibilities and share the same benefits. Only one cohabitee is recognized in Canada. A common-law relationship cannot be established with more than one person at the same time. If the sponsor is legally married to someone else, officers must be satisfied that the sponsor is separated from and no longer cohabits with the legal spouse.
The common-law spouse shall declare the relationship by submitting the "Statutory Declaration of Common-Law Union", Form IMM 5409, and take an oath before a Commissioner of Oaths. Proof that both parties have lived together for more than one year is also required when filing the immigration application. Supporting documents that your show residential address include but are not limited to: water and electrical bills, credit card bills, phone bills, rental contracts, third party testimonies, etc.
In the case of common-law partners that are unmarried and not able to live together, as long as both parties maintain a stable marriage-like relationship, they can also reunite and immigrate. This relationship is called a Conjugal Partner in Canadian law. Note that a conjugal relationship differs from a common-law relationship.