The Income Tax Act treats spouses and common-law partners the same way. However, it is important to understand what the terms mean. A “spouse” is someone to whom you are legally married. The definition of a “common-law partner”, on the other hand, depends on whether or not you have children.
If you start cohabitating with someone who is the parent of your child, you are considered to be common-law partners from the time you move in together. A “parent”, for this purpose, includes an adoptive parent (whether in law or in fact) as well as a natural parent.
If there are no children involved, you only become common-law partners after you have lived together in a conjugal relationship for 12 continuous months. The 12-month period includes any period during which you were separated